2020-01-07 11:53:42

by Peter Ujfalusi

Subject: [PATCH v2] media: stm32-dcmi: Use dma_request_chan() instead dma_request_slave_channel()

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <[email protected]>
---
Hi,

Changes since v1:
- Do not print error for EPROBE_DEFER

Regards,
Peter

drivers/media/platform/stm32/stm32-dcmi.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 9392e3409fba..b63ff8d636ce 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -1910,10 +1910,13 @@ static int dcmi_probe(struct platform_device *pdev)
return PTR_ERR(mclk);
}

- chan = dma_request_slave_channel(&pdev->dev, "tx");
- if (!chan) {
- dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
- return -EPROBE_DEFER;
+ chan = dma_request_chan(&pdev->dev, "tx");
+ if (IS_ERR(chan)) {
+ ret = PTR_ERR(chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Failed to request DMA channel: %d\n", ret);
+ return ret;
}

spin_lock_init(&dcmi->irqlock);
--
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

2020-01-07 13:40:40

by Hugues Fruchet

Subject: Re: [PATCH v2] media: stm32-dcmi: Use dma_request_chan() instead dma_request_slave_channel()

Acked-by: Hugues Fruchet <[email protected]>

On 1/7/20 12:52 PM, Peter Ujfalusi wrote:
> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> eating up the error code.
>
> By using dma_request_chan() directly the driver can support deferred
> probing against DMA.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> Hi,
>
> Changes since v1:
> - Do not print error for EPROBE_DEFER
>
> Regards,
> Peter
>
> drivers/media/platform/stm32/stm32-dcmi.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index 9392e3409fba..b63ff8d636ce 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -1910,10 +1910,13 @@ static int dcmi_probe(struct platform_device *pdev)
> return PTR_ERR(mclk);
> }
>
> - chan = dma_request_slave_channel(&pdev->dev, "tx");
> - if (!chan) {
> - dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
> - return -EPROBE_DEFER;
> + chan = dma_request_chan(&pdev->dev, "tx");
> + if (IS_ERR(chan)) {
> + ret = PTR_ERR(chan);
> + if (ret != -EPROBE_DEFER)
> + dev_err(&pdev->dev,
> + "Failed to request DMA channel: %d\n", ret);
> + return ret;
> }
>
> spin_lock_init(&dcmi->irqlock);
>