Re: [PATCH 2/3] dma: add __must_check annotation for dmaengine_pause()

[Peter Hurley <peter@hurleysoftware.com>]

On 08/07/2015 04:00 PM, Sebastian Andrzej Siewior wrote:
> In 8250-omap I learned it the hard way that ignoring the return code
> of dmaengine_pause() might be bad because the underlying DMA driver
> might not support the function at all and so not doing what one is
> expecting.
> This patch adds the __must_check annotation as suggested by Russell King.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  include/linux/dmaengine.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 8ad9a4e839f6..4eac4716bded 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -825,7 +825,7 @@ static inline int dmaengine_terminate_all(struct dma_chan *chan)
>  	return -ENOSYS;
>  }
>  
> -static inline int dmaengine_pause(struct dma_chan *chan)
> +static inline int __must_check dmaengine_pause(struct dma_chan *chan)
>  {
>  	if (chan->device->device_pause)
>  		return chan->device->device_pause(chan);
> 

Not that this is your responsibility, Sebastian, but considering there are
fewer than 20 users of dmaengine_pause() in the entire tree, we should add
WARN_ON_ONCE() around those uses with this patch to avoid a bunch needless
one-off "fixes".

Regards,
Peter Hurley