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V4L/DVB (6085): cx88-alsa: Fix mmap support 

The driver has long claimed to support mmap, but it didn't work at all.  Some
of the dma buffer parameters weren't set, and since video_buf uses vmalloc to
allocate the buffer, a page callback is needed too.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Trent Piepho 2007-08-24 01:06:36 -03:00 committed by Mauro Carvalho Chehab
parent ffb7394d51
commit f6210c9160
1 changed files with 14 additions and 0 deletions
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14
drivers/media/video/cx88/cx88-alsa.c
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@ -28,6 +28,7 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/vmalloc.h>
#include <linux/dma-mapping.h>
#include <linux/pci.h>
@ -423,6 +424,8 @@ static int snd_cx88_hw_params(struct snd_pcm_substream * substream,
chip->dma_risc = buf->vb.dma;
substream->runtime->dma_area = chip->dma_risc.vmalloc;
substream->runtime->dma_bytes = chip->dma_size;
substream->runtime->dma_addr = 0;
return 0;
error:
@ -499,6 +502,16 @@ static snd_pcm_uframes_t snd_cx88_pointer(struct snd_pcm_substream *substream)
return runtime->period_size * (count & (runtime->periods-1));
}
/*
* page callback (needed for mmap)
*/
static struct page *snd_cx88_page(struct snd_pcm_substream *substream,
unsigned long offset)
{
void *pageptr = substream->runtime->dma_area + offset;
return vmalloc_to_page(pageptr);
}
/*
* operators
*/
@ -511,6 +524,7 @@ static struct snd_pcm_ops snd_cx88_pcm_ops = {
.prepare = snd_cx88_prepare,
.trigger = snd_cx88_card_trigger,
.pointer = snd_cx88_pointer,
.page = snd_cx88_page,
};
/*