question about sound/oss/vidc.c

question about sound/oss/vidc.c

[Julia Lawall]

In sound/oss/vidc.c, the function vidc_audio_trigger contains thefollowing 
code:

        struct audio_operations *adev = audio_devs[dev];

        if (enable_bits & PCM_ENABLE_OUTPUT) {
                if (!(adev->flags & DMA_ACTIVE)) {
                        unsigned long flags;

                        local_irq_save(flags);

                        /* prevent recusion */
                        adev->flags |= DMA_ACTIVE;

			...
		}
	}

I wonder if the use of DMA_ACTIVE is correct?  This constant is defined 
inthe file sound/oss/dev_table.h within the definition of the structure 
dma_buffparms.  But here it is being used with the structure 
audio_operations.  The definition of audio_operations also contains the 
definitions of some constants.  Indeed, one of them, DMA_DUPLEX has the 
same value as DMA_ACTIVE.

thanks,
julia

Re: question about sound/oss/vidc.c

[Takashi Iwai]

[Cc'ed to Russell, the driver author]

At Tue, 16 Mar 2010 23:02:54 +0100 (CET),
Julia Lawall wrote:
> 
> In sound/oss/vidc.c, the function vidc_audio_trigger contains thefollowing 
> code:
> 
>         struct audio_operations *adev = audio_devs[dev];
> 
>         if (enable_bits & PCM_ENABLE_OUTPUT) {
>                 if (!(adev->flags & DMA_ACTIVE)) {
>                         unsigned long flags;
> 
>                         local_irq_save(flags);
> 
>                         /* prevent recusion */
>                         adev->flags |= DMA_ACTIVE;
> 
> 			...
> 		}
> 	}
> 
> I wonder if the use of DMA_ACTIVE is correct?  This constant is defined 
> inthe file sound/oss/dev_table.h within the definition of the structure 
> dma_buffparms.  But here it is being used with the structure 
> audio_operations.  The definition of audio_operations also contains the 
> definitions of some constants.  Indeed, one of them, DMA_DUPLEX has the 
> same value as DMA_ACTIVE.

I guess these should be adev->dma_out->flags instead.


thanks,

Takashi

Re: question about sound/oss/vidc.c

[Russell King]

On Wed, Mar 17, 2010 at 08:25:52AM +0100, Takashi Iwai wrote:
> I guess these should be adev->dma_out->flags instead.

Yes, I think so too.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:

Re: question about sound/oss/vidc.c

[Julia Lawall]

On Sat, 20 Mar 2010, Russell King wrote:

> On Wed, Mar 17, 2010 at 08:25:52AM +0100, Takashi Iwai wrote:
> > I guess these should be adev->dma_out->flags instead.
> 
> Yes, I think so too.

Thanks. I sent a patch.

julia