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

From: Peter Ujfalusi
Date: Tue Jan 07 2020 - 06:52:36 EST


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 <peter.ujfalusi@xxxxxx>
---
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

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