[alsa-devel] question about sound/oss/vidc.c

Julia Lawall julia at diku.dk
Tue Mar 16 23:02:54 CET 2010

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

        struct audio_operations *adev = audio_devs[dev];

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


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