Le 22/11/2021 à 07:56, Vinod Koul a écrit :
On 09-11-21, 22:09, Christophe JAILLET wrote:
The commit in the Fixes: tag has changed the logic of the code and now it
is likely that the probe will return an early success (0), even if not
completely executed.
This should lead to a crash or similar issue later on when the code
accesses to some never allocated resources.
Change the '!err' into a 'err' when checking if
'dma_set_mask_and_coherent()' has failed or not.
While at it, simplify the code and remove the "can't success code" related
to 32 DMA mask.
As stated in [1], 'dma_set_mask_and_coherent(DMA_BIT_MASK(64))' can't fail
if 'dev->dma_mask' is non-NULL. And if it is NULL, it would fail for the
same reason when tried with DMA_BIT_MASK(32).
The patch title should describe the changes in the patch and not the
outcome! So I have taken the liberty to update this to:
dmaengine: dw-edma: Fix return value check for dma_set_mask_and_coherent()
Hi,
In fact, this 'bad' patch title was a way for me to express my
frustration to someone who 'stole' someone else work:
- without letting him know about it
- without fixing his broken patch by himself when informed
- without taking into account others comments (Andy Shevchenko about
64 DMA mask)
So, thanks for fixing it (and thanks to Wang Qing for pushing in the
right direction, even if a better communication would have been
appreciated :) )
If you could just confirmed the 64 DMA mask cleanup, it would be great
for me. I trust the one who stated that such code could be simplified
and I've tried to audit code to confirm it by myself.
However, this pattern looks quite common in the kernel, so I'm still
unsure about it :( !
CJ
