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| author | Trent Piepho <xyzzy@speakeasy.org> | 2007-10-31 07:40:09 -0700 |
|---|---|---|
| committer | Trent Piepho <xyzzy@speakeasy.org> | 2007-10-31 07:40:09 -0700 |
| commit | 1816a3983b8c8a4ed5e9ba32b1eade0ce9499809 (patch) | |
| tree | 553dd25c790b126899793485406ed1f90a51f5d4 /linux/drivers/media/video | |
| parent | eaf6bdcc22aa742bdec32708647fe07d891631db (diff) | |
| download | mediapointer-dvb-s2-1816a3983b8c8a4ed5e9ba32b1eade0ce9499809.tar.gz mediapointer-dvb-s2-1816a3983b8c8a4ed5e9ba32b1eade0ce9499809.tar.bz2 | |
saa7134-alsa: Fix mmap support
From: Alexander E. Patrakov <patrakov@ums.usu.ru>
Trent Piepho wrote:
> I do not think the saa7134-alsa driver supports mmap. The cx88-alsa driver
> also claimed to support mmap, but it never worked until I fixed it. It's
> pretty clear that the code in saa7134-alsa was based on the same code as
> cx88-alsa, so it's likely it has the same bug.
You are right. The patch below (based on your cx88 patch, but I don't
really understand it) fixes mmap support in saa7134-alsa for me.
Recording via mmap (arecord -M -f S16_LE -c 2 -r 32000 -D hw:1) didn't
work at all before, works now, tested for at least 20 minutes (but,
unfortunately, with one overrun at least 0.719 ms long).
Signed-off-by: Alexander E. Patrakov <patrakov@ums.usu.ru>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Diffstat (limited to 'linux/drivers/media/video')
| -rw-r--r-- | linux/drivers/media/video/saa7134/saa7134-alsa.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/linux/drivers/media/video/saa7134/saa7134-alsa.c b/linux/drivers/media/video/saa7134/saa7134-alsa.c index 9b557ab7c..a2ee5cf9c 100644 --- a/linux/drivers/media/video/saa7134/saa7134-alsa.c +++ b/linux/drivers/media/video/saa7134/saa7134-alsa.c @@ -557,8 +557,10 @@ static int snd_card_saa7134_hw_params(struct snd_pcm_substream * substream, V4L functions, and force ALSA to use that as the DMA area */ substream->runtime->dma_area = dev->dmasound.dma.vmalloc; + substream->runtime->dma_bytes = dev->dmasound.bufsize; + substream->runtime->dma_addr = 0; - return 1; + return 0; } @@ -666,6 +668,17 @@ static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream) } /* + * page callback (needed for mmap) + */ + +static struct page *snd_card_saa7134_page(struct snd_pcm_substream *substream, + unsigned long offset) +{ + void *pageptr = substream->runtime->dma_area + offset; + return vmalloc_to_page(pageptr); +} + +/* * ALSA capture callbacks definition */ @@ -678,6 +691,7 @@ static struct snd_pcm_ops snd_card_saa7134_capture_ops = { .prepare = snd_card_saa7134_capture_prepare, .trigger = snd_card_saa7134_capture_trigger, .pointer = snd_card_saa7134_capture_pointer, + .page = snd_card_saa7134_page, }; /* |