AM335x BeagleBone SPI Issues

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

Hi,

Quoted 22 lines · Jack Mitchell

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

Quoted 6 lines

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

cheers

Quoted 23 lines · Jack Mitchell

Quoted 22 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

Quoted 8 lines

Quoted 6 lines

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

edge, clk normal

The initial dmesg statup log is at [2].

Quoted 2 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

However it did work flawlessly with 3.2-psp.

Hi,

Quoted 49 lines · Jack Mitchell

Quoted 23 lines · Jack Mitchell

Quoted 22 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

Quoted 8 lines

Quoted 6 lines

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

Quoted 3 lines

edge, clk normal

The initial dmesg statup log is at [2].

can you apply the debugging patch below to spi driver and show me the output again ?

Note that I'm allowing DMA for as small as 1-byte transfers (as you needed) and I'm also disabling DMA Request line before calling complete() as I think the current way could race, but likely wouldn't cause issues. Anyway, please show me the output.

drivers/spi/spi-omap2-mcspi.c +13 -5

index 3542fdc..d2b1af2 100644
@@ -108,7 +108,7 @@ struct omap2_mcspi_dma {
  /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
   * cache operations; better heuristics consider wordsize and bitrate.
   */
-#define DMA_MIN_BYTES			160
+#define DMA_MIN_BYTES			1
 
 
  /*

@@ -298,10 +298,11 @@ static void omap2_mcspi_rx_callback(void *data)
  	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
  	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
-	complete(&mcspi_dma->dma_rx_completion);
-
  	/* We must disable the DMA RX request */
+	dev_info(&spi->dev, "Disabling RX Request Line\n");
  	omap2_mcspi_set_dma_req(spi, 1, 0);
+
+	complete(&mcspi_dma->dma_rx_completion);
  }
 
  static void omap2_mcspi_tx_callback(void *data)

@@ -310,10 +311,11 @@ static void omap2_mcspi_tx_callback(void *data)
  	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
  	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
-	complete(&mcspi_dma->dma_tx_completion);
-
  	/* We must disable the DMA TX request */
+	dev_info(&spi->dev, "Disabling TX Request Line\n");
  	omap2_mcspi_set_dma_req(spi, 0, 0);
+
+	complete(&mcspi_dma->dma_tx_completion);
  }
 
  static void omap2_mcspi_tx_dma(struct spi_device *spi,

@@ -328,6 +330,7 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	void __iomem		*chstat_reg;
  	struct omap2_mcspi_cs	*cs = spi->controller_state;
 
+	dev_info(&spi->dev, "kicking TX DMA\n");
  	mcspi = spi_master_get_devdata(spi->master);
  	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
  	count = xfer->len;

@@ -359,7 +362,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	dma_async_issue_pending(mcspi_dma->dma_tx);
  	omap2_mcspi_set_dma_req(spi, 0, 1);
 
+	dev_info(&spi->dev, "Waiting for TX Completion\n");
  	wait_for_completion(&mcspi_dma->dma_tx_completion);
+	dev_info(&spi->dev, "TX Completed\n");
  	dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
  			 DMA_TO_DEVICE);
 

@@ -392,6 +397,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
  	word_len = cs->word_len;
  	l = mcspi_cached_chconf0(spi);
 
+	dev_info(&spi->dev, "kicking RX DMA\n");
  	if (word_len <= 8)
  		element_count = count;
  	else if (word_len <= 16)

@@ -428,7 +434,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
  	dma_async_issue_pending(mcspi_dma->dma_rx);
  	omap2_mcspi_set_dma_req(spi, 1, 1);
 
+	dev_info(&spi->dev, "Waiting for RX Completion\n");
  	wait_for_completion(&mcspi_dma->dma_rx_completion);
+	dev_info(&spi->dev, "RX Completed\n");
  	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
  			 DMA_FROM_DEVICE);
  	omap2_mcspi_set_enable(spi, 0);

Quoted 7 lines

Quoted 3 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

no problem ;-)

Quoted 1 line

However it did work flawlessly with 3.2-psp.

yeah, it could be some regression introduced somewhere, or just a bugfix which was done on 3.2-psp and was missed upstream... annoying when those happen :-p

Quoted 152 lines · Felipe Balbi

Hi,

Quoted 57 lines · Jack Mitchell

Quoted 28 lines · Jack Mitchell

Quoted 26 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

Quoted 7 lines

Quoted 4 lines

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3]
http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max -->
0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max
--> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max
--> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

Quoted 3 lines

edge, clk normal

The initial dmesg statup log is at [2].

can you apply the debugging patch below to spi driver and show me the output again ?

Note that I'm allowing DMA for as small as 1-byte transfers (as you needed) and I'm also disabling DMA Request line before calling complete() as I think the current way could race, but likely wouldn't cause issues. Anyway, please show me the output.

drivers/spi/spi-omap2-mcspi.c +8 -3

index 3542fdc..d2b1af2 100644
@@ -108,7 +108,7 @@ struct omap2_mcspi_dma {
  /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
   * cache operations; better heuristics consider wordsize and bitrate.
   */
-#define DMA_MIN_BYTES                  160
+#define DMA_MIN_BYTES                  1
      /*

@@ -298,10 +298,11 @@ static void omap2_mcspi_rx_callback(void *data)
        struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
        struct omap2_mcspi_dma *mcspi_dma =
 &mcspi->dma_channels[spi->chip_select];
  -     complete(&mcspi_dma->dma_rx_completion);
-
        /* We must disable the DMA RX request */
+       dev_info(&spi->dev, "Disabling RX Request Line\n");
        omap2_mcspi_set_dma_req(spi, 1, 0);
+
+       complete(&mcspi_dma->dma_rx_completion);
  }
    static void omap2_mcspi_tx_callback(void *data)

@@ -310,10 +311,11 @@ static void omap2_mcspi_tx_callback(void *data)
        struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
        struct omap2_mcspi_dma *mcspi_dma =
 &mcspi->dma_channels[spi->chip_select];
  -     complete(&mcspi_dma->dma_tx_completion);
-
        /* We must disable the DMA TX request */
+       dev_info(&spi->dev, "Disabling TX Request Line\n");
        omap2_mcspi_set_dma_req(spi, 0, 0);
+
+       complete(&mcspi_dma->dma_tx_completion);
  }
    static void omap2_mcspi_tx_dma(struct spi_device *spi,

@@ -328,6 +330,7 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
        void __iomem            *chstat_reg;
        struct omap2_mcspi_cs   *cs = spi->controller_state;
  +     dev_info(&spi->dev, "kicking TX DMA\n");
        mcspi = spi_master_get_devdata(spi->master);
        mcspi_dma = &mcspi->dma_channels[spi->chip_select];
        count = xfer->len;

@@ -359,7 +362,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
        dma_async_issue_pending(mcspi_dma->dma_tx);
        omap2_mcspi_set_dma_req(spi, 0, 1);
  +     dev_info(&spi->dev, "Waiting for TX Completion\n");
        wait_for_completion(&mcspi_dma->dma_tx_completion);
+       dev_info(&spi->dev, "TX Completed\n");
        dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
                         DMA_TO_DEVICE);
  @@ -392,6 +397,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct

spi_transfer *xfer,

        word_len = cs->word_len;
        l = mcspi_cached_chconf0(spi);
  +     dev_info(&spi->dev, "kicking RX DMA\n");
        if (word_len <= 8)
                element_count = count;
        else if (word_len <= 16)

drivers/spi/spi-omap2-mcspi.c +1 -0

@@ -428,7 +434,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct
 spi_transfer *xfer,
        dma_async_issue_pending(mcspi_dma->dma_rx);
        omap2_mcspi_set_dma_req(spi, 1, 1);
  +     dev_info(&spi->dev, "Waiting for RX Completion\n");
        wait_for_completion(&mcspi_dma->dma_rx_completion);
+       dev_info(&spi->dev, "RX Completed\n");
        dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
                         DMA_FROM_DEVICE);
        omap2_mcspi_set_enable(spi, 0);

Quoted 8 lines

Quoted 3 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

Quoted 8 lines

no problem ;-)

Quoted 1 line

However it did work flawlessly with 3.2-psp.

yeah, it could be some regression introduced somewhere, or just a bugfix which was done on 3.2-psp and was missed upstream... annoying when those happen :-p

Quoted 145 lines · Jack Mitchell

Quoted 144 lines · Felipe Balbi

Hi,

Quoted 53 lines · Jack Mitchell

Quoted 26 lines · Jack Mitchell

Quoted 25 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

Quoted 6 lines

Quoted 4 lines

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3]
http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max -->
0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max
--> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max
--> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

Quoted 3 lines

edge, clk normal

The initial dmesg statup log is at [2].

can you apply the debugging patch below to spi driver and show me the output again ?

Note that I'm allowing DMA for as small as 1-byte transfers (as you needed) and I'm also disabling DMA Request line before calling complete() as I think the current way could race, but likely wouldn't cause issues. Anyway, please show me the output.

drivers/spi/spi-omap2-mcspi.c +8 -3

index 3542fdc..d2b1af2 100644
@@ -108,7 +108,7 @@ struct omap2_mcspi_dma {
   /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
    * cache operations; better heuristics consider wordsize and bitrate.
    */
-#define DMA_MIN_BYTES                  160
+#define DMA_MIN_BYTES                  1
       /*

@@ -298,10 +298,11 @@ static void omap2_mcspi_rx_callback(void *data)
         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
         struct omap2_mcspi_dma *mcspi_dma =
 &mcspi->dma_channels[spi->chip_select];
   -     complete(&mcspi_dma->dma_rx_completion);
-
         /* We must disable the DMA RX request */
+       dev_info(&spi->dev, "Disabling RX Request Line\n");
         omap2_mcspi_set_dma_req(spi, 1, 0);
+
+       complete(&mcspi_dma->dma_rx_completion);
   }
     static void omap2_mcspi_tx_callback(void *data)

@@ -310,10 +311,11 @@ static void omap2_mcspi_tx_callback(void *data)
         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
         struct omap2_mcspi_dma *mcspi_dma =
 &mcspi->dma_channels[spi->chip_select];
   -     complete(&mcspi_dma->dma_tx_completion);
-
         /* We must disable the DMA TX request */
+       dev_info(&spi->dev, "Disabling TX Request Line\n");
         omap2_mcspi_set_dma_req(spi, 0, 0);
+
+       complete(&mcspi_dma->dma_tx_completion);
   }
     static void omap2_mcspi_tx_dma(struct spi_device *spi,

@@ -328,6 +330,7 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
         void __iomem            *chstat_reg;
         struct omap2_mcspi_cs   *cs = spi->controller_state;
   +     dev_info(&spi->dev, "kicking TX DMA\n");
         mcspi = spi_master_get_devdata(spi->master);
         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
         count = xfer->len;

@@ -359,7 +362,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
         dma_async_issue_pending(mcspi_dma->dma_tx);
         omap2_mcspi_set_dma_req(spi, 0, 1);
   +     dev_info(&spi->dev, "Waiting for TX Completion\n");
         wait_for_completion(&mcspi_dma->dma_tx_completion);
+       dev_info(&spi->dev, "TX Completed\n");
         dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
                          DMA_TO_DEVICE);
   @@ -392,6 +397,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct

spi_transfer *xfer,

         word_len = cs->word_len;
         l = mcspi_cached_chconf0(spi);
   +     dev_info(&spi->dev, "kicking RX DMA\n");
         if (word_len <= 8)
                 element_count = count;
         else if (word_len <= 16)

drivers/spi/spi-omap2-mcspi.c +1 -0

@@ -428,7 +434,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct
 spi_transfer *xfer,
         dma_async_issue_pending(mcspi_dma->dma_rx);
         omap2_mcspi_set_dma_req(spi, 1, 1);
   +     dev_info(&spi->dev, "Waiting for RX Completion\n");
         wait_for_completion(&mcspi_dma->dma_rx_completion);
+       dev_info(&spi->dev, "RX Completed\n");
         dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
                          DMA_FROM_DEVICE);
         omap2_mcspi_set_enable(spi, 0);

Quoted 7 lines

Quoted 3 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

Quoted 7 lines

Quoted 7 lines

no problem ;-)

Quoted 1 line

However it did work flawlessly with 3.2-psp.

yeah, it could be some regression introduced somewhere, or just a bugfix which was done on 3.2-psp and was missed upstream... annoying when those happen :-p

Can you try the following

git://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git spi-next

Alternatively you can use the linux-next.

And let me know if you still see the issue.
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Quoted 136 lines · Felipe Balbi

Hi,

Quoted 49 lines · Jack Mitchell

Quoted 23 lines · Jack Mitchell

Quoted 22 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

Quoted 8 lines

Quoted 6 lines

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

Quoted 3 lines

edge, clk normal

The initial dmesg statup log is at [2].

can you apply the debugging patch below to spi driver and show me the output again ?

Note that I'm allowing DMA for as small as 1-byte transfers (as you needed) and I'm also disabling DMA Request line before calling complete() as I think the current way could race, but likely wouldn't cause issues. Anyway, please show me the output.

drivers/spi/spi-omap2-mcspi.c +13 -5

index 3542fdc..d2b1af2 100644
@@ -108,7 +108,7 @@ struct omap2_mcspi_dma {
 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
  * cache operations; better heuristics consider wordsize and bitrate.
  */
-#define DMA_MIN_BYTES			160
+#define DMA_MIN_BYTES			1
 /*

@@ -298,10 +298,11 @@ static void omap2_mcspi_rx_callback(void *data)
 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
-	complete(&mcspi_dma->dma_rx_completion);
-
 	/* We must disable the DMA RX request */
+	dev_info(&spi->dev, "Disabling RX Request Line\n");
 	omap2_mcspi_set_dma_req(spi, 1, 0);
+
+	complete(&mcspi_dma->dma_rx_completion);
 }
 static void omap2_mcspi_tx_callback(void *data)

@@ -310,10 +311,11 @@ static void omap2_mcspi_tx_callback(void *data)
 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
-	complete(&mcspi_dma->dma_tx_completion);
-
 	/* We must disable the DMA TX request */
+	dev_info(&spi->dev, "Disabling TX Request Line\n");
 	omap2_mcspi_set_dma_req(spi, 0, 0);
+
+	complete(&mcspi_dma->dma_tx_completion);
 }
 static void omap2_mcspi_tx_dma(struct spi_device *spi,

@@ -328,6 +330,7 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
 	void __iomem		*chstat_reg;
 	struct omap2_mcspi_cs	*cs = spi->controller_state;
+	dev_info(&spi->dev, "kicking TX DMA\n");
 	mcspi = spi_master_get_devdata(spi->master);
 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 	count = xfer->len;

@@ -359,7 +362,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
 	dma_async_issue_pending(mcspi_dma->dma_tx);
 	omap2_mcspi_set_dma_req(spi, 0, 1);
+	dev_info(&spi->dev, "Waiting for TX Completion\n");
 	wait_for_completion(&mcspi_dma->dma_tx_completion);
+	dev_info(&spi->dev, "TX Completed\n");
 	dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
 			 DMA_TO_DEVICE);

@@ -392,6 +397,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	word_len = cs->word_len;
 	l = mcspi_cached_chconf0(spi);
+	dev_info(&spi->dev, "kicking RX DMA\n");
 	if (word_len <= 8)
 		element_count = count;
 	else if (word_len <= 16)

@@ -428,7 +434,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	dma_async_issue_pending(mcspi_dma->dma_rx);
 	omap2_mcspi_set_dma_req(spi, 1, 1);
+	dev_info(&spi->dev, "Waiting for RX Completion\n");
 	wait_for_completion(&mcspi_dma->dma_rx_completion);
+	dev_info(&spi->dev, "RX Completed\n");
 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
 			 DMA_FROM_DEVICE);
 	omap2_mcspi_set_enable(spi, 0);
 

Quoted 6 lines

Quoted 2 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

Quoted 7 lines

no problem ;-)

Quoted 1 line

However it did work flawlessly with 3.2-psp.

yeah, it could be some regression introduced somewhere, or just a bugfix which was done on 3.2-psp and was missed upstream... annoying when those happen :-p

Your patch didn't apply cleanly but I hacked it in and got the following:

[   40.434566] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434609] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   40.434622] spidev spi1.0: spi mode 00
[   40.434645] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434661] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   40.434673] spidev spi1.0: 16 bits per word
[   40.434692] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434708] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   40.434720] spidev spi1.0: 24000000 Hz (max)
[   40.439300] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.439397] spidev spi1.0: kicking TX DMA
[   40.443797] spidev spi1.0: Waiting for TX Completion

Shubhro, what do you think ? could this be the case ?

Hi,

Quoted 146 lines · Jack Mitchell

Quoted 136 lines · Felipe Balbi

Hi,

Quoted 49 lines · Jack Mitchell

Quoted 23 lines · Jack Mitchell

Quoted 22 lines

Hi,

I am currently having issues with the SPI driver on the beaglebone using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have found that writing works however reading doesn't. When using DMA the program seems to lock hard and no data is sent on the bus. I am testing the bus using spidev and the spidev_test[2] application, however I first came across spi issues with a custom spi driver which stopped working when I transitioned from 3.2-psp to 3.7-rc8.

The current output I am seeing from the spidev_test program is just a series of 0x00 data, which looks to me like no data is getting in at all. The spidev_test program is not using DMA as the buffer size is too low, so I forced the dma on when buffer size is > 1 and the program hangs hard with the system still responding to other commands.I have briged the pins 18 and 21 on the BeagleBone P9 header.

Has anyone seen issues like this, or if not if someone could please test the latest 3.7-rc8 from [1] and let me know if it works for them and the issue is at my end.

Quoted 8 lines

Quoted 6 lines

To get spidev working with devicetree I applied the patch from [3] and changed the dtb as in the patch pasted below.

[1] https://github.com/beagleboard/kernel/tree/3.7
[2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c
[3] http://www.mail-archive.com/[email protected]/msg09958.html

do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers.

When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is:

[   12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <----
Last line from initial log in [2]
[   47.669202] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   47.669260] spidev spi1.0: spi mode 00
[   47.669283] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669312] spidev spi1.0: 16 bits per word
[   47.669330] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   47.669358] spidev spi1.0: 24000000 Hz (max)
[   47.673811] spidev spi1.0: setup: speed 24000000, sample leading

Quoted 3 lines

edge, clk normal

The initial dmesg statup log is at [2].

can you apply the debugging patch below to spi driver and show me the output again ?

Note that I'm allowing DMA for as small as 1-byte transfers (as you needed) and I'm also disabling DMA Request line before calling complete() as I think the current way could race, but likely wouldn't cause issues. Anyway, please show me the output.

drivers/spi/spi-omap2-mcspi.c +13 -5

index 3542fdc..d2b1af2 100644
@@ -108,7 +108,7 @@ struct omap2_mcspi_dma {
  /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
   * cache operations; better heuristics consider wordsize and bitrate.
   */
-#define DMA_MIN_BYTES			160
+#define DMA_MIN_BYTES			1
  /*

@@ -298,10 +298,11 @@ static void omap2_mcspi_rx_callback(void *data)
  	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
  	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
-	complete(&mcspi_dma->dma_rx_completion);
-
  	/* We must disable the DMA RX request */
+	dev_info(&spi->dev, "Disabling RX Request Line\n");
  	omap2_mcspi_set_dma_req(spi, 1, 0);
+
+	complete(&mcspi_dma->dma_rx_completion);
  }
  static void omap2_mcspi_tx_callback(void *data)

@@ -310,10 +311,11 @@ static void omap2_mcspi_tx_callback(void *data)
  	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
  	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
-	complete(&mcspi_dma->dma_tx_completion);
-
  	/* We must disable the DMA TX request */
+	dev_info(&spi->dev, "Disabling TX Request Line\n");
  	omap2_mcspi_set_dma_req(spi, 0, 0);
+
+	complete(&mcspi_dma->dma_tx_completion);
  }
  static void omap2_mcspi_tx_dma(struct spi_device *spi,

@@ -328,6 +330,7 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	void __iomem		*chstat_reg;
  	struct omap2_mcspi_cs	*cs = spi->controller_state;
+	dev_info(&spi->dev, "kicking TX DMA\n");
  	mcspi = spi_master_get_devdata(spi->master);
  	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
  	count = xfer->len;

@@ -359,7 +362,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	dma_async_issue_pending(mcspi_dma->dma_tx);
  	omap2_mcspi_set_dma_req(spi, 0, 1);
+	dev_info(&spi->dev, "Waiting for TX Completion\n");
  	wait_for_completion(&mcspi_dma->dma_tx_completion);
+	dev_info(&spi->dev, "TX Completed\n");
  	dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
  			 DMA_TO_DEVICE);

@@ -392,6 +397,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
  	word_len = cs->word_len;
  	l = mcspi_cached_chconf0(spi);
+	dev_info(&spi->dev, "kicking RX DMA\n");
  	if (word_len <= 8)
  		element_count = count;
  	else if (word_len <= 16)

@@ -428,7 +434,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
  	dma_async_issue_pending(mcspi_dma->dma_rx);
  	omap2_mcspi_set_dma_req(spi, 1, 1);
+	dev_info(&spi->dev, "Waiting for RX Completion\n");
  	wait_for_completion(&mcspi_dma->dma_rx_completion);
+	dev_info(&spi->dev, "RX Completed\n");
  	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
  			 DMA_FROM_DEVICE);
  	omap2_mcspi_set_enable(spi, 0);
 

Quoted 6 lines

Quoted 2 lines

It would also be nice to have a clear picture of what "custom spi driver" you're talking about.

The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :)

Quoted 7 lines

no problem ;-)

Quoted 1 line

However it did work flawlessly with 3.2-psp.

yeah, it could be some regression introduced somewhere, or just a bugfix which was done on 3.2-psp and was missed upstream... annoying when those happen :-p

Your patch didn't apply cleanly but I hacked it in and got the following:

Quoted 16 lines

[   40.434566] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434609] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0
[   40.434622] spidev spi1.0: spi mode 00
[   40.434645] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434661] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   40.434673] spidev spi1.0: 16 bits per word
[   40.434692] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.434708] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0
[   40.434720] spidev spi1.0: 24000000 Hz (max)
[   40.439300] spidev spi1.0: setup: speed 24000000, sample leading
edge, clk normal
[   40.439397] spidev spi1.0: kicking TX DMA
[   40.443797] spidev spi1.0: Waiting for TX Completion

so TX dma never completes... perhaps all you need is Shubhro's commit reordering TX and RX calls ??

commit e47a682ace0cd56eb8e09b806c2b0f034b491520

Author: Shubhrajyoti D <[email protected]>
Date:   Tue Nov 6 14:30:19 2012 +0530

spi: omap2-mcspi: Reorder the wait_for_completion for tx

The commit d7b4394e[Cleanup the omap2_mcspi_txrx_dma function] changed the wait_for_completion order. Move the wait so that the rx doesnot wait for the tx to complete.

Reported-and-tested-by Sørensen, Stefan <[email protected]>

Signed-off-by Shubhrajyoti D <[email protected]>

Signed-off-by Mark Brown <[email protected]>

drivers/spi/spi-omap2-mcspi.c +19 -20

index 3542fdc..b1a651e 100644
@@ -323,18 +323,13 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	struct omap2_mcspi	*mcspi;
  	struct omap2_mcspi_dma  *mcspi_dma;
  	unsigned int		count;
-	u8			* rx;
  	const u8		* tx;
-	void __iomem		*chstat_reg;
-	struct omap2_mcspi_cs	*cs = spi->controller_state;
 
  	mcspi = spi_master_get_devdata(spi->master);
  	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
  	count = xfer->len;
 
-	rx = xfer->rx_buf;
  	tx = xfer->tx_buf;
-	chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 
  	if (mcspi_dma->dma_tx) {
  		struct dma_async_tx_descriptor *tx;

@@ -359,19 +354,6 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
  	dma_async_issue_pending(mcspi_dma->dma_tx);
  	omap2_mcspi_set_dma_req(spi, 0, 1);
 
-	wait_for_completion(&mcspi_dma->dma_tx_completion);
-	dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
-			 DMA_TO_DEVICE);
-
-	/* for TX_ONLY mode, be sure all words have shifted out */
-	if (rx == NULL) {
-		if (mcspi_wait_for_reg_bit(chstat_reg,
-					OMAP2_MCSPI_CHSTAT_TXS) < 0)
-			dev_err(&spi->dev, "TXS timed out\n");
-		else if (mcspi_wait_for_reg_bit(chstat_reg,
-					OMAP2_MCSPI_CHSTAT_EOT) < 0)
-			dev_err(&spi->dev, "EOT timed out\n");
-	}
  }
 
  static unsigned

@@ -492,6 +474,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
  	struct dma_slave_config	cfg;
  	enum dma_slave_buswidth width;
  	unsigned es;
+	void __iomem		*chstat_reg;
 
  	mcspi = spi_master_get_devdata(spi->master);
  	mcspi_dma = &mcspi->dma_channels[spi->chip_select];

@@ -526,8 +509,24 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
  		omap2_mcspi_tx_dma(spi, xfer, cfg);
 
  	if (rx != NULL)
-		return omap2_mcspi_rx_dma(spi, xfer, cfg, es);
-
+		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
+
+	if (tx != NULL) {
+		chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+		wait_for_completion(&mcspi_dma->dma_tx_completion);
+		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
+				 DMA_TO_DEVICE);
+
+		/* for TX_ONLY mode, be sure all words have shifted out */
+		if (rx == NULL) {
+			if (mcspi_wait_for_reg_bit(chstat_reg,
+						OMAP2_MCSPI_CHSTAT_TXS) < 0)
+				dev_err(&spi->dev, "TXS timed out\n");
+			else if (mcspi_wait_for_reg_bit(chstat_reg,
+						OMAP2_MCSPI_CHSTAT_EOT) < 0)
+				dev_err(&spi->dev, "EOT timed out\n");
+		}
+	}
  	return count;
  }
 

Shubhro, what do you think ? could this be the case ?

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Thank you for the help so far.

Hi,

On Tue, Dec 11, 2012 at 10:17:42AM +0000, Jack Mitchell wrote:

<big snip>

Quoted 6 lines

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

<removed spidev_test output>

Quoted 8 lines

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Quoted 1 line

Thank you for the help so far.

according to the schematics [1], those pins are muxed as UART2_TXD and I2C1_SDA, have you remuxed them properly ? Can you try with pins 29 and 30 on the same header ? That's SPI1, so you will have to add DT data for spidev on that bus too.

[1] http://beagleboard.org/static/beaglebone/latest/Docs/Hardware/BONE_SCH.pdf

Quoted 22 lines · Felipe Balbi

Hi,

On Tue, Dec 11, 2012 at 10:17:42AM +0000, Jack Mitchell wrote:

<big snip>

Quoted 6 lines

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

<removed spidev_test output>

Quoted 8 lines

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Quoted 8 lines

Quoted 1 line

Thank you for the help so far.

according to the schematics [1], those pins are muxed as UART2_TXD and I2C1_SDA, have you remuxed them properly ? Can you try with pins 29 and 30 on the same header ? That's SPI1, so you will have to add DT data for spidev on that bus too.

[1] http://beagleboard.org/static/beaglebone/latest/Docs/Hardware/BONE_SCH.pdf

No change unfortunately:

root@beaglebone:~# ./spidev
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00

root@beaglebone:~# ./spidev -D /dev/s
shm/       spidev1.0  spidev2.0  stderr     stdin      stdout
root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00
root@beaglebone:~#

Quoted 47 lines · Jack Mitchell

Quoted 22 lines · Felipe Balbi

Hi,

On Tue, Dec 11, 2012 at 10:17:42AM +0000, Jack Mitchell wrote:

<big snip>

Quoted 6 lines

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

<removed spidev_test output>

Quoted 8 lines

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Quoted 8 lines

Quoted 1 line

Thank you for the help so far.

according to the schematics [1], those pins are muxed as UART2_TXD and I2C1_SDA, have you remuxed them properly ? Can you try with pins 29 and 30 on the same header ? That's SPI1, so you will have to add DT data for spidev on that bus too.

[1] http://beagleboard.org/static/beaglebone/latest/Docs/Hardware/BONE_SCH.pdf

No change unfortunately:

root@beaglebone:~# ./spidev
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00

Quoted 3 lines

root@beaglebone:~# ./spidev -D /dev/s
shm/       spidev1.0  spidev2.0  stderr     stdin      stdout
root@beaglebone:~# ./spidev -D /dev/spidev2.0

Hi again,

Quoted 47 lines · Felipe Balbi

Quoted 46 lines · Jack Mitchell

Quoted 22 lines · Felipe Balbi

Hi,

On Tue, Dec 11, 2012 at 10:17:42AM +0000, Jack Mitchell wrote:

<big snip>

Quoted 6 lines

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

<removed spidev_test output>

Quoted 8 lines

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Quoted 8 lines

Quoted 1 line

Thank you for the help so far.

according to the schematics [1], those pins are muxed as UART2_TXD and I2C1_SDA, have you remuxed them properly ? Can you try with pins 29 and 30 on the same header ? That's SPI1, so you will have to add DT data for spidev on that bus too.

[1] http://beagleboard.org/static/beaglebone/latest/Docs/Hardware/BONE_SCH.pdf

No change unfortunately:

root@beaglebone:~# ./spidev
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00

Quoted 3 lines

Quoted 3 lines

root@beaglebone:~# ./spidev -D /dev/s
shm/       spidev1.0  spidev2.0  stderr     stdin      stdout
root@beaglebone:~# ./spidev -D /dev/spidev2.0

one thing caught my attention, shouldn't you be passing '-l' argument here for loopback testing ? That would mean you need to make sure your "spi->mode" has SPI_LOOP flag set. Currently there is no way to do that via DeviceTree (AFAICT), so please apply ths patch to your tree and set spi-loopback; property for your spidev entry:

Documentation/devicetree/bindings/spi/spi-bus.txt +2 -0

index 296015e..1949586 100644
@@ -55,6 +55,8 @@ contain the following properties.
      		chip select active high
  - spi-3wire       - (optional) Empty property indicating device requires
      		    3-wire mode.
+- spi-loopback    - (optional) Empty property indicating device requires
+    		    loopback mode.
 
  If a gpio chipselect is used for the SPI slave the gpio number will be passed
  via the cs_gpio

drivers/spi/spi.c +0 -0

index 3f1b9ee..6bcdc03 100644

Quoted 76 lines · Felipe Balbi

Hi again,

Quoted 47 lines · Felipe Balbi

Quoted 46 lines · Jack Mitchell

Quoted 22 lines · Felipe Balbi

Hi,

On Tue, Dec 11, 2012 at 10:17:42AM +0000, Jack Mitchell wrote:

<big snip>

Quoted 6 lines

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

<removed spidev_test output>

Quoted 8 lines

dmesg shows nothing of interest apart from the spi bus setting up. Any ideas?

To iterate for my own sanity; I have bridged pins 18 and 21 on the P9 header which should be the d0 and d1 spi data pins for spi0. This result of 0x00 usually comes from a result of not joining the pins, but I can assure you they are joined!

Quoted 8 lines

Quoted 1 line

Thank you for the help so far.

according to the schematics [1], those pins are muxed as UART2_TXD and I2C1_SDA, have you remuxed them properly ? Can you try with pins 29 and 30 on the same header ? That's SPI1, so you will have to add DT data for spidev on that bus too.

[1] http://beagleboard.org/static/beaglebone/latest/Docs/Hardware/BONE_SCH.pdf

No change unfortunately:

root@beaglebone:~# ./spidev
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00

Quoted 3 lines

Quoted 3 lines

root@beaglebone:~# ./spidev -D /dev/s
shm/       spidev1.0  spidev2.0  stderr     stdin      stdout
root@beaglebone:~# ./spidev -D /dev/spidev2.0

one thing caught my attention, shouldn't you be passing '-l' argument here for loopback testing ? That would mean you need to make sure your "spi->mode" has SPI_LOOP flag set. Currently there is no way to do that via DeviceTree (AFAICT), so please apply ths patch to your tree and set spi-loopback; property for your spidev entry:

Documentation/devicetree/bindings/spi/spi-bus.txt +2 -0

index 296015e..1949586 100644
@@ -55,6 +55,8 @@ contain the following properties.
     		chip select active high
 - spi-3wire       - (optional) Empty property indicating device requires
     		    3-wire mode.
+- spi-loopback    - (optional) Empty property indicating device requires
+    		    loopback mode.
 If a gpio chipselect is used for the SPI slave the gpio number will be passed
 via the cs_gpio

drivers/spi/spi.c +0 -0

index 3f1b9ee..6bcdc03 100644

drivers/spi/spi.c static void of_register_spi_devices(struct spi_master *master) · line 875

Quoted 8 lines

drivers/spi/spi.c +2 -0

@@ -868,6 +868,8 @@ static void of_register_spi_devices(struct spi_master *master)
 			spi->mode |= SPI_CS_HIGH;
 		if (of_find_property(nc, "spi-3wire", NULL))
 			spi->mode |= SPI_3WIRE;
+		if (of_find_property(nc, "spi-loopback", NULL))
+			spi->mode |= SPI_LOOP;
 		/* Device speed */
 		prop = of_get_property(nc, "spi-max-frequency", &len);
 

I get the following error when I apply this patch and add spi-loopback.

&spi0 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&spi0_pins>;

  spidev0: spidev@0 {
  compatible = "linux,spidev";
  reg = <0>;
  spi-max-frequency = <24000000>;
  spi-loopback;
  };

};

[    1.093565] omap2_mcspi 48030000.spi: registered master spi1
[    1.094491] spi spi1.0: setup: unsupported mode bits 20
[    1.100035] omap2_mcspi 48030000.spi: can't setup spi1.0, status -22
[    1.106715] spi_master spi1: spi_device register error
/ocp/spi@48030000/spidev@0
[    1.115030] omap2_mcspi 481a0000.spi: registered master spi2
[    1.115710] spi spi2.0: setup: unsupported mode bits 20
[    1.121225] omap2_mcspi 481a0000.spi: can't setup spi2.0, status -22
[    1.127903] spi_master spi2: spi_device register error

/ocp/spi@481a0000/spidev@0

I have run this test many times before and have never needed to use a loopback...

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Quoted 7 lines · Jack Mitchell

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

Cheers,

- Ben

Quoted 3 lines · Ben Gamari

Jack Mitchell <[email protected]> writes:

<snip>

Almost.

I then tried spi1 and received:

root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF

root@beaglebone:~# ./spidev_dma -D /dev/spidev2.0
spi mode: 0
bits per word: 8
max speed: 500000 Hz (500 KHz)

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
root@beaglebone:~#

Quoted 9 lines · Ben Gamari

Quoted 7 lines · Jack Mitchell

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Quoted 7 lines

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

Cheers,

- Ben

Ok, Ben, well spotted indeed! I changed the dtsi to use INPUT_PULLUP instead of OUTPUT_PULLUP and wallah!

  am3358_pinmux: pinmux@44e10800 {
    spi0_pins: pinmux_spi0_pins {
      pinctrl-single,pins = <
        0x150 *0x30*      /* spi0_sclk.gpio0_2, INPUT_PULLUP | MODE0 
*/<------------ changed to INPUT
        0x154 0x30      /* spi0_d0.gpio0_3, INPUT_PULLUP | MODE0 */
        0x158 0x10      /* spi0_d1.i2c1_sda, OUTPUT_PULLUP | MODE0 */
        0x15c 0x10      /* spi0_cs0.i2c1_scl, OUTPUT_PULLUP | MODE0 */
      >;
    };
    spi1_pins: pinmux_spi1_pins {
      pinctrl-single,pins = <
        0x190 *0x33*  /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 
*/ <------------ changed to INPUT
        0x194 0x33  /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
        0x198 0x13  /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
        0x19c 0x13  /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
      >;
    };

root@beaglebone:~# ./spidev
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D

root@beaglebone:~# ./spidev_dma
spi mode: 0
bits per word: 8
max speed: 500000 Hz (500 KHz)

FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00
FF 00 FF 00 FF 00

We are in business!

Almost.

I then tried spi1 and received:

root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF

root@beaglebone:~# ./spidev_dma -D /dev/spidev2.0
spi mode: 0
bits per word: 8
max speed: 500000 Hz (500 KHz)

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF

FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
root@beaglebone:~#

Quoted 10 lines · Jack Mitchell

Quoted 9 lines · Ben Gamari

Quoted 6 lines · Jack Mitchell

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine,
the reading from the program still shows 0x00 for all words.

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

My bad! The jumper bridge had come loose, it works now! Yippee!

root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D
root@beaglebone:~#

Thanks everyone, and do I need to submit any patches to clear this all up?

Currently all I see is changing the clk pins from output to input (if this is a valid change?).

Hi,

Quoted 11 lines · Jack Mitchell

Quoted 10 lines · Jack Mitchell

Quoted 9 lines · Ben Gamari

Quoted 6 lines · Jack Mitchell

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine,
the reading from the program still shows 0x00 for all words.

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

*snip*

Quoted 18 lines

My bad! The jumper bridge had come loose, it works now! Yippee!

root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D
root@beaglebone:~#

Thanks everyone, and do I need to submit any patches to clear this all up?

Quoted 2 lines

Currently all I see is changing the clk pins from output to input (if this is a valid change?).

I just stumbled over the same problem and have not seen any patch for this fix. Have I missed something or should I send a patch? Which would be the correct base for such a patch?

Regards,
Jan

Quoted 36 lines · Jan Lübbe

Hi,

Quoted 11 lines · Jack Mitchell

Quoted 10 lines · Jack Mitchell

Quoted 9 lines · Ben Gamari

Quoted 6 lines · Jack Mitchell

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine,
the reading from the program still shows 0x00 for all words.

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

*snip*

Quoted 20 lines

My bad! The jumper bridge had come loose, it works now! Yippee!

root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 KHz)

FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D
root@beaglebone:~#

Thanks everyone, and do I need to submit any patches to clear this all up?

Currently all I see is changing the clk pins from output to input (if this is a valid change?).

Quoted 6 lines

I just stumbled over the same problem and have not seen any patch for this fix. Have I missed something or should I send a patch? Which would be the correct base for such a patch?

Regards,
Jan

I didn't submit a patch for this but easily could. I was confused about what tree to base it against as at the time (may still be the same) DT SPI for AM335x was not in a mainline tree. I hoped someone would pick it up when posting DT SPI for mainline....

Quoted 9 lines · Ben Gamari

Quoted 7 lines · Jack Mitchell

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Quoted 7 lines

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

Cheers,

- Ben

Ok, Ben, well spotted indeed! I changed the dtsi to use INPUT_PULLUP instead of OUTPUT_PULLUP and wallah!

  am3358_pinmux: pinmux@44e10800 {
    spi0_pins: pinmux_spi0_pins {
      pinctrl-single,pins = <
        0x150 *0x30*      /* spi0_sclk.gpio0_2, INPUT_PULLUP | MODE0
*/<------------ changed to INPUT
        0x154 0x30      /* spi0_d0.gpio0_3, INPUT_PULLUP | MODE0 */
        0x158 0x10      /* spi0_d1.i2c1_sda, OUTPUT_PULLUP | MODE0 */
        0x15c 0x10      /* spi0_cs0.i2c1_scl, OUTPUT_PULLUP | MODE0 */
      >;
    };
    spi1_pins: pinmux_spi1_pins {

      pinctrl-single,pins = <
        0x190 *0x33*  /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3
*/ <------------ changed to INPUT
        0x194 0x33  /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
        0x198 0x13  /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
        0x19c 0x13  /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
      >;
    };

Hi,

Quoted 32 lines · Jack Mitchell

Quoted 9 lines · Ben Gamari

Quoted 7 lines · Jack Mitchell

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Quoted 7 lines

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

Cheers,

- Ben

Ok, Ben, well spotted indeed! I changed the dtsi to use INPUT_PULLUP instead of OUTPUT_PULLUP and wallah!

  am3358_pinmux: pinmux@44e10800 {
    spi0_pins: pinmux_spi0_pins {
      pinctrl-single,pins = <
        0x150 *0x30*      /* spi0_sclk.gpio0_2, INPUT_PULLUP | MODE0
*/<------------ changed to INPUT
        0x154 0x30      /* spi0_d0.gpio0_3, INPUT_PULLUP | MODE0 */
        0x158 0x10      /* spi0_d1.i2c1_sda, OUTPUT_PULLUP | MODE0 */
        0x15c 0x10      /* spi0_cs0.i2c1_scl, OUTPUT_PULLUP | MODE0 */
      >;
    };
    spi1_pins: pinmux_spi1_pins {

Quoted 8 lines

      pinctrl-single,pins = <
        0x190 *0x33*  /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3
*/ <------------ changed to INPUT
        0x194 0x33  /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
        0x198 0x13  /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
        0x19c 0x13  /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
      >;
    };

funny, I did the same on my pandaboard and it still didn't work :-s

Hi,

Quoted 47 lines · Felipe Balbi

Hi,

Quoted 32 lines · Jack Mitchell

Quoted 9 lines · Ben Gamari

Quoted 7 lines · Jack Mitchell

Shubhro, Felipe,

Thank you, the reordering dma patch fixed the dma issue I was having! However, the bad news, I now get the same results for the dma and non-dma spidev test. While the scope shows the SPI clk and data is fine, the reading from the program still shows 0x00 for all words.

Quoted 7 lines

Just to make sure this has been thought of: I've seen this sort of behavior in the past when the CLK pin wasn't configured as an input.

Cheers,

- Ben

Ok, Ben, well spotted indeed! I changed the dtsi to use INPUT_PULLUP instead of OUTPUT_PULLUP and wallah!

  am3358_pinmux: pinmux@44e10800 {
    spi0_pins: pinmux_spi0_pins {
      pinctrl-single,pins = <
        0x150 *0x30*      /* spi0_sclk.gpio0_2, INPUT_PULLUP | MODE0
*/<------------ changed to INPUT
        0x154 0x30      /* spi0_d0.gpio0_3, INPUT_PULLUP | MODE0 */
        0x158 0x10      /* spi0_d1.i2c1_sda, OUTPUT_PULLUP | MODE0 */
        0x15c 0x10      /* spi0_cs0.i2c1_scl, OUTPUT_PULLUP | MODE0 */
      >;
    };
    spi1_pins: pinmux_spi1_pins {

Quoted 8 lines

      pinctrl-single,pins = <
        0x190 *0x33*  /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3
*/ <------------ changed to INPUT
        0x194 0x33  /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
        0x198 0x13  /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
        0x19c 0x13  /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
      >;
    };

funny, I did the same on my pandaboard and it still didn't work :-s

Review static struct omap_board_mux board_mux[] __initdata = { · line 327

Quoted 6 lines

(quoted diff) +3 -0

@@ -321,6 +322,10 @@ static struct omap_board_mux board_mux[] __initdata = {
        OMAP4_MUX(SDMMC5_DAT1, OMAP_MUX_MODE0 | OMAP_PIN_INPUT_PULLUP),
        OMAP4_MUX(SDMMC5_DAT2, OMAP_MUX_MODE0 | OMAP_PIN_INPUT_PULLUP),
        OMAP4_MUX(SDMMC5_DAT3, OMAP_MUX_MODE0 | OMAP_PIN_INPUT_PULLUP),
+
+       /* SPI1 */
+       OMAP4_MUX(MCSPI1_CLK, OMAP_MUX_MODE0 | OMAP_PIN_INPUT_PULLUP),

hehe, I'll reply to my own nonsense. Of course this won't work, I'm not muxing the other MCSPI pins :-p

I'll do that tomorrow and test, cheers