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dmaengine: Fix return value for dma_requrest_chan() in case of failure

Message ID 20200129163548.11096-1-m.szyprowski@samsung.com (mailing list archive)
State Changes Requested
Headers show
Series dmaengine: Fix return value for dma_requrest_chan() in case of failure | expand

Commit Message

Marek Szyprowski Jan. 29, 2020, 4:35 p.m. UTC
Commit 71723a96b8b1 ("dmaengine: Create symlinks between DMA channels and
slaves") changed the dma_request_chan() function flow in such a way that
it always returns EPROBE_DEFER in case of channels that cannot be found.
This break the operation of the devices which have optional DMA channels
as it puts their drivers in endless deferred probe loop. Fix this by
propagating the proper error value.

Fixes: 71723a96b8b1 ("dmaengine: Create symlinks between DMA channels and slaves")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/dma/dmaengine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Peter Ujfalusi Jan. 29, 2020, 7:51 p.m. UTC | #1
On 29/01/2020 18.35, Marek Szyprowski wrote:
> Commit 71723a96b8b1 ("dmaengine: Create symlinks between DMA channels and
> slaves") changed the dma_request_chan() function flow in such a way that
> it always returns EPROBE_DEFER in case of channels that cannot be found.
> This break the operation of the devices which have optional DMA channels
> as it puts their drivers in endless deferred probe loop. Fix this by
> propagating the proper error value.
> 
> Fixes: 71723a96b8b1 ("dmaengine: Create symlinks between DMA channels and slaves")
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/dma/dmaengine.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index f3ef4edd4de1..27b64a665347 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -759,7 +759,7 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
>  	if (!IS_ERR_OR_NULL(chan))
>  		goto found;
>  
> -	return ERR_PTR(-EPROBE_DEFER);
> +	return chan;

It should be:
return chan ? chan : ERR_PTR(-EPROBE_DEFER);

dma_request_chan() should never return NULL, it either returns the
dma_chan, or ERR_PTR().

>  
>  found:
>  	chan->slave = dev;
> 

- Péter

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diff mbox series

Patch

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index f3ef4edd4de1..27b64a665347 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -759,7 +759,7 @@  struct dma_chan *dma_request_chan(struct device *dev, const char *name)
 	if (!IS_ERR_OR_NULL(chan))
 		goto found;
 
-	return ERR_PTR(-EPROBE_DEFER);
+	return chan;
 
 found:
 	chan->slave = dev;