[PATCH v2 1/1] spi: spi-imx: Use dev_err_probe for failed DMA channel requests

[PATCH v2 1/1] spi: spi-imx: Use dev_err_probe for failed DMA channel requests

[Alexander Stein]

If dma_request_chan() fails, no error is shown nor any information is
shown in /sys/kernel/debug/devices_deferred if -EPROBE_DEFER is returned.
Use dev_err_probe to fix both problems.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
Sorry, I lost sight of the replies from v1 series. I'll address Fabio's
concern here instead.

It's true that running spi-imx with SDMA is valid. But if provided DMA
channels are not available, aka -EPROBE_DEFER, there is no information
why so. This can simply be seen by disabling the sdma1 node on imx8mp:
$ cat /sys/kernel/debug/devices_deferred 
30820000.spi
30830000.spi
30840000.spi

There is no indication what is wrong/missing here. There is also no fallback
to pio mode.
This patch addresses this by setting the defer probe reason.

Changes in v2:
* Rebase to next-20240110

[1] https://lore.kernel.org/all/CAOMZO5CcD5iDkaempdxnQHx1fAgnXAmMq_0MdEq5wNgOLHcMuw@mail.gmail.com/

 drivers/spi/spi-imx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 272bc871a848b..546cdce525fc5 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1344,7 +1344,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	controller->dma_tx = dma_request_chan(dev, "tx");
 	if (IS_ERR(controller->dma_tx)) {
 		ret = PTR_ERR(controller->dma_tx);
-		dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
+		dev_err_probe(dev, ret, "can't get the TX DMA channel!\n");
 		controller->dma_tx = NULL;
 		goto err;
 	}
@@ -1353,7 +1353,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	controller->dma_rx = dma_request_chan(dev, "rx");
 	if (IS_ERR(controller->dma_rx)) {
 		ret = PTR_ERR(controller->dma_rx);
-		dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
+		dev_err_probe(dev, ret, "can't get the RX DMA channel!\n");
 		controller->dma_rx = NULL;
 		goto err;
 	}
-- 
2.34.1

Re: [PATCH v2 1/1] spi: spi-imx: Use dev_err_probe for failed DMA channel requests

[Francesco Dolcini]

On Wed, Jan 10, 2024 at 09:54:03AM +0100, Alexander Stein wrote:
> If dma_request_chan() fails, no error is shown nor any information is
> shown in /sys/kernel/debug/devices_deferred if -EPROBE_DEFER is returned.
> Use dev_err_probe to fix both problems.
> 
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>

Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>

Re: [PATCH v2 1/1] spi: spi-imx: Use dev_err_probe for failed DMA channel requests

[Mark Brown]

On Wed, 10 Jan 2024 09:54:03 +0100, Alexander Stein wrote:
> If dma_request_chan() fails, no error is shown nor any information is
> shown in /sys/kernel/debug/devices_deferred if -EPROBE_DEFER is returned.
> Use dev_err_probe to fix both problems.
> 
> 

Applied to

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

Thanks!

[1/1] spi: spi-imx: Use dev_err_probe for failed DMA channel requests
      commit: fbc7ee6cc16918ea64a963a4ee097699cc159a8d

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