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

From	Andy Shevchenko <andy.shevchenko@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in __dma_device_satisfies_mask()
Date	2015-11-30 15:40 +0100
Message-ID	<qAxMt-4Or-5@gated-at.bofh.it> (permalink)
References	<qAx05-4hY-3@gated-at.bofh.it> <qAx06-4hY-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Nov 30, 2015 at 3:45 PM, Peter Ujfalusi <peter.ujfalusi@ti.com> 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@ti.com>
> ---
>  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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Thread

[RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in __dma_device_satisfies_mask() Peter Ujfalusi <peter.ujfalusi@ti.com> - 2015-11-30 14:50 +0100
  Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in __dma_device_satisfies_mask() Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-11-30 15:40 +0100
    Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in  __dma_device_satisfies_mask() Peter Ujfalusi <peter.ujfalusi@ti.com> - 2015-12-01 10:50 +0100
      Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in __dma_device_satisfies_mask() Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-12-01 14:00 +0100
        Re: [RFC v02 01/15] dmaengine: core: Allow NULL mask pointer in  __dma_device_satisfies_mask() Vinod Koul <vinod.koul@intel.com> - 2015-12-01 18:10 +0100

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