ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel

PATCH In review Roger Quadros 3 participants 6 messages Jun 24, 2015 – Jul 13, 2015

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Roger Quadros

author

2015-06-24 14:00 UTC #0 lore raw

PATCH 1/1 ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel

If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.

"omap_hwmod: dcan1: _wait_target_disable failed"

This is because DCAN1 module's SWAKEUP mechanism is broken and it fails to correctly turn OFF if it sees a transition on the DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode while enabling/disabling DCAN1 module.

The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.

DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.

Signed-off-by Roger Quadros <[email protected]>

---
 board/ti/dra7xx/mux_data.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

board/ti/dra7xx/mux_data.h +2 -2

index c9301a5..91e00b9 100644
@@ -358,7 +358,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
 	{SPI2_D1, (M1 | PIN_INPUT_SLEW)},	/* spi2_d1.uart3_txd */
 	{SPI2_D0, (M1 | PIN_INPUT_SLEW)},	/* spi2_d0.uart3_ctsn */
 	{SPI2_CS0, (M1 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* spi2_cs0.uart3_rtsn */
-	{DCAN1_TX, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_tx.dcan1_tx */
+	{DCAN1_TX, (M15 | PULL_UP)},	/* dcan1_tx.safe for dcan1_tx */
 	{DCAN1_RX, (M14 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_rx.gpio1_15 */
 	{UART1_RXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_rxd.uart1_rxd */
 	{UART1_TXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_txd.uart1_txd */

@@ -370,7 +370,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
 	{UART2_RTSN, (M3 | PIN_INPUT_PULLUP)},	/* uart2_rtsn.mmc4_dat3 */
 	{I2C2_SDA, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_sda.i2c2_sda */
 	{I2C2_SCL, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_scl.i2c2_scl */
-	{WAKEUP0, (M1 | PIN_OUTPUT)},	/* Wakeup0.dcan1_rx */
+	{WAKEUP0, (M15 | PULL_UP)},	/* Wakeup0.safe for dcan1_rx */
 	{WAKEUP2, (M14 | PIN_OUTPUT)},	/* Wakeup2.gpio1_2 */
 };

Signature · 1 line

2.1.4

Nishanth Menon

2015-06-24 17:40 UTC #1 lore raw

PATCH 1/1 ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel

Quoted 39 lines · Roger Quadros

If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.
"omap_hwmod: dcan1: _wait_target_disable failed"
This is because DCAN1 module's SWAKEUP mechanism is broken and it fails to correctly turn OFF if it sees a transition on the DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode while enabling/disabling DCAN1 module.
The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.
DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.
Signed-off-by Roger Quadros <[email protected]>
---
 board/ti/dra7xx/mux_data.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
board/ti/dra7xx/mux_data.h +1 -1
index c9301a5..91e00b9 100644
@@ -358,7 +358,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
 	{SPI2_D1, (M1 | PIN_INPUT_SLEW)},	/* spi2_d1.uart3_txd */
 	{SPI2_D0, (M1 | PIN_INPUT_SLEW)},	/* spi2_d0.uart3_ctsn */
 	{SPI2_CS0, (M1 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* spi2_cs0.uart3_rtsn */
-	{DCAN1_TX, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_tx.dcan1_tx */
+	{DCAN1_TX, (M15 | PULL_UP)},	/* dcan1_tx.safe for dcan1_tx */
 	{DCAN1_RX, (M14 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_rx.gpio1_15 */
 	{UART1_RXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_rxd.uart1_rxd */
 	{UART1_TXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_txd.uart1_txd */

board/ti/dra7xx/mux_data.h const struct pad_conf_entry dra74x_core_padconf_array[] = { · line 376

Quoted 8 lines

board/ti/dra7xx/mux_data.h +1 -1

@@ -370,7 +370,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
 	{UART2_RTSN, (M3 | PIN_INPUT_PULLUP)},	/* uart2_rtsn.mmc4_dat3 */
 	{I2C2_SDA, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_sda.i2c2_sda */
 	{I2C2_SCL, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_scl.i2c2_scl */
-	{WAKEUP0, (M1 | PIN_OUTPUT)},	/* Wakeup0.dcan1_rx */
+	{WAKEUP0, (M15 | PULL_UP)},	/* Wakeup0.safe for dcan1_rx */
 	{WAKEUP2, (M14 | PIN_OUTPUT)},	/* Wakeup2.gpio1_2 */
 };

LGTM, could you also look at x15 platform?

Signature · 2 lines

Regards,
Nishanth Menon

Roger Quadros

author

2015-06-25 07:25 UTC #2 lore raw

PATCH 2/2 ARM: beagle_x15: prevent DCAN1 _wait_target_disable failure in kernel

In reply to Roger Quadros

If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.

"omap_hwmod: dcan1: _wait_target_disable failed"

The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.

DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.

Signed-off-by Roger Quadros <[email protected]>

---
 board/ti/beagle_x15/mux_data.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

board/ti/beagle_x15/mux_data.h +2 -2

index 09d3650..da2610c 100644
@@ -244,8 +244,8 @@ const struct pad_conf_entry core_padconf_array_essential[] = {
 	{SPI2_D1, (M14 | PIN_INPUT_PULLDOWN)},	/* spi2_d1.gpio7_15 */
 	{SPI2_D0, (M14 | PIN_INPUT_PULLUP)},	/* spi2_d0.gpio7_16 */
 	{SPI2_CS0, (M14 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* spi2_cs0.gpio7_17 */
-	{DCAN1_TX, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_tx.dcan1_tx */
-	{DCAN1_RX, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_rx.dcan1_rx */
+	{DCAN1_TX, (M15 | PULLUP)},	/* dcan1_tx.safe for dcan1_tx */
+	{DCAN1_RX, (M15 | PULLUP)},	/* dcan1_rx.safe for dcan1_rx */
 	{UART1_RXD, (M0 | PIN_INPUT_SLEW)},	/* uart1_rxd.uart1_rxd */
 	{UART1_TXD, (M0 | PIN_INPUT_SLEW)},	/* uart1_txd.uart1_txd */
 	{UART1_CTSN, (M15 | PIN_INPUT_PULLDOWN)},	/* uart1_ctsn.Driveroff */

Signature · 1 line

2.1.4

Tom Rini

2015-07-10 12:57 UTC #3 lore raw

PATCH 2/2 ARM: beagle_x15: prevent DCAN1 _wait_target_disable failure in kernel

Quoted 15 lines · Roger Quadros

If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.
"omap_hwmod: dcan1: _wait_target_disable failed"
This is because DCAN1 module's SWAKEUP mechanism is broken and it fails to correctly turn OFF if it sees a transition on the DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode while enabling/disabling DCAN1 module.
The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.

Quoted 5 lines

DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.
Signed-off-by Roger Quadros <[email protected]>

With %s/PULLUP/PULL_UP/ based on the DRA7xx patch, applied to u-boot/master, thanks!

Signature · 8 lines

Tom
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Roger Quadros

author

2015-07-13 10:41 UTC #4 lore raw

PATCH 2/2 ARM: beagle_x15: prevent DCAN1 _wait_target_disable failure in kernel

Quoted 17 lines · Tom Rini

Quoted 15 lines · Roger Quadros
If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.
"omap_hwmod: dcan1: _wait_target_disable failed"
This is because DCAN1 module's SWAKEUP mechanism is broken and it fails to correctly turn OFF if it sees a transition on the DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode while enabling/disabling DCAN1 module.
The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.

Quoted 9 lines

Quoted 5 lines
DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.
Signed-off-by Roger Quadros <[email protected]>
With %s/PULLUP/PULL_UP/ based on the DRA7xx patch, applied to u-boot/master, thanks!

Thanks Tom :).

cheers,
-roger

Tom Rini

2015-07-10 12:56 UTC #5 lore raw

In reply to Roger Quadros

Quoted 15 lines · Roger Quadros

If board is booted with transitions happening on DCAN1 pins then the following warning is seen in the kernel at boot when the hwmod layer initializes.
"omap_hwmod: dcan1: _wait_target_disable failed"
This is because DCAN1 module's SWAKEUP mechanism is broken and it fails to correctly turn OFF if it sees a transition on the DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode while enabling/disabling DCAN1 module.
The hwmod layer enables and disables all modules at boot and we have no opportunity to put the DCAN1 pins in safe mode at that point.

Quoted 5 lines

DCAN1 is not used by u-boot so it doesn't matter to it if these pins are in safe mode. The kernel driver correctly configures the right mode when DCAN1 is active.
Signed-off-by Roger Quadros <[email protected]>

Applied to u-boot/master, thanks!

Signature · 8 lines

Tom
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