spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer

PATCH In review Akinobu Mita 2 participants 2 messages Mar 22, 2017 – Mar 24, 2017 1 message not in the archive SPI

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Akinobu Mita

author

2017-03-22 00:18 UTC #0 lore raw

PATCH 1/1 spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer

When running the spi-loopback-test with slower clock rate like 10 KHz, the test for 251 bytes transfer was failed. This failure triggered an spi-omap2-mcspi's error message "DMA RX last word empty".

This message means that PIO for reading the remaining bytes due to the DMA transfer length reduction is failed. This problem can be fixed by polling OMAP2_MCSPI_CHSTAT_RXS bit in channel status register to wait until the receive buffer register is filled.

Cc Mark Brown <[email protected]>

Signed-off-by Akinobu Mita <[email protected]>

---
 drivers/spi/spi-omap2-mcspi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

drivers/spi/spi-omap2-mcspi.c +5 -4

index 79800e9..7275223 100644
@@ -454,6 +454,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	int			elements = 0;
 	int			word_len, element_count;
 	struct omap2_mcspi_cs	*cs = spi->controller_state;
+	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+
 	mcspi = spi_master_get_devdata(spi->master);
 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 	count = xfer->len;

@@ -549,8 +551,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
 		elements--;
 
-		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
-				   & OMAP2_MCSPI_CHSTAT_RXS)) {
+		if (!mcspi_wait_for_reg_bit(chstat_reg,
+					    OMAP2_MCSPI_CHSTAT_RXS)) {
 			u32 w;
 
 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);

@@ -568,8 +570,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 			return count;
 		}
 	}
-	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
-				& OMAP2_MCSPI_CHSTAT_RXS)) {
+	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
 		u32 w;
 
 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);

Signature · 6 lines

2.7.4

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A message that is not in the archive (sent off-list or not yet received): 1490141906-8908-1-git-send-email-akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

Mark Brown

2017-03-24 19:16 UTC #2 lore raw

Applied "spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer" to the spi tree

The patch

spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer

has been applied to the spi tree at

git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks,
Mark

Quoted 1 line

From 812613591cb652344186c4cd912304ed02138566 Mon Sep 17 00:00:00 2001

From: Akinobu Mita <[email protected]>
Date: Wed, 22 Mar 2017 09:18:26 +0900
Subject: [PATCH] spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO
transfer

When running the spi-loopback-test with slower clock rate like 10 KHz, the test for 251 bytes transfer was failed. This failure triggered an spi-omap2-mcspi's error message "DMA RX last word empty".

Cc Mark Brown <[email protected]>

Signed-off-by Akinobu Mita <[email protected]>

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

---
 drivers/spi/spi-omap2-mcspi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

drivers/spi/spi-omap2-mcspi.c +5 -4

index 79800e991ccd..7275223dbcd4 100644
@@ -454,6 +454,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	int			elements = 0;
 	int			word_len, element_count;
 	struct omap2_mcspi_cs	*cs = spi->controller_state;
+	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+
 	mcspi = spi_master_get_devdata(spi->master);
 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 	count = xfer->len;

@@ -549,8 +551,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
 		elements--;
 
-		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
-				   & OMAP2_MCSPI_CHSTAT_RXS)) {
+		if (!mcspi_wait_for_reg_bit(chstat_reg,
+					    OMAP2_MCSPI_CHSTAT_RXS)) {
 			u32 w;
 
 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);

@@ -568,8 +570,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 			return count;
 		}
 	}
-	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
-				& OMAP2_MCSPI_CHSTAT_RXS)) {
+	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
 		u32 w;
 
 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);

Signature · 6 lines

2.11.0

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