Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in __dma_device_satisfies_mask()

[Andy Shevchenko]

On Mon, Nov 30, 2015 at 3:45 PM, Peter Ujfalusi <peter.ujfalusi@xxxxxx> wrote:
> Treat as true condition the case when the mask is NULL.

What do you think about setting some default (all "on") mask when mask
is not supplied?

I don't know for sure but there might be cases when you don't want
literally *any* channel to satisfy.

>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
>  drivers/dma/dmaengine.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index daf54a39bcc7..52c3eee48e2e 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -184,6 +184,9 @@ __dma_device_satisfies_mask(struct dma_device *device,
>  {
>         dma_cap_mask_t has;
>
> +       if (!want)
> +               return true;
> +
>         bitmap_and(has.bits, want->bits, device->cap_mask.bits,
>                 DMA_TX_TYPE_END);
>         return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
> --
> 2.6.3
>



-- 
With Best Regards,
Andy Shevchenko
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