[alsa-devel] [PATCH] [ALSA] mpc8610: Add mmap support
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's default mmap functionality, it was just not enabled previously.
Signed-off-by: Timur Tabi timur@freescale.com --- sound/soc/fsl/fsl_dma.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c index 2173203..652514f 100644 --- a/sound/soc/fsl/fsl_dma.c +++ b/sound/soc/fsl/fsl_dma.c @@ -136,7 +136,9 @@ struct fsl_dma_private { */ static const struct snd_pcm_hardware fsl_dma_hardware = {
- .info = SNDRV_PCM_INFO_INTERLEAVED, + .info = SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID, .formats = FSLDMA_PCM_FORMATS, .rates = FSLDMA_PCM_RATES, .rate_min = 5512,
Timur Tabi wrote:
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's default mmap functionality, it was just not enabled previously.
Signed-off-by: Timur Tabi timur@freescale.com
[sorry, I may be completely wrong below about the .page callback purpose - in this case, just confirm that the testcase works]
Hm, the "struct snd_pcm_ops fsl_dma_ops" doesn't contain the .page callback. With saa7134-alsa, this led to the "device claims to support mmap but actually doesn't work" bug, see the following subthread:
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-October/003773.htm...
IOW: have you actually tested that the following commands work (X,Y refer to the FSL chip)?
aplay -M -D hw:X,Y sample.wav arecord -f cd -M -D:X,Y capture.wav
sound/soc/fsl/fsl_dma.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c index 2173203..652514f 100644 --- a/sound/soc/fsl/fsl_dma.c +++ b/sound/soc/fsl/fsl_dma.c @@ -136,7 +136,9 @@ struct fsl_dma_private { */ static const struct snd_pcm_hardware fsl_dma_hardware = {
- .info = SNDRV_PCM_INFO_INTERLEAVED,
- .info = SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_MMAP |SNDRV_PCM_INFO_MMAP_VALID,
Alexander E. Patrakov wrote:
Timur Tabi wrote:
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's default mmap functionality, it was just not enabled previously.
Signed-off-by: Timur Tabi timur@freescale.com
[sorry, I may be completely wrong below about the .page callback purpose
- in this case, just confirm that the testcase works]
Hm, the "struct snd_pcm_ops fsl_dma_ops" doesn't contain the .page callback. With saa7134-alsa, this led to the "device claims to support mmap but actually doesn't work" bug, see the following subthread:
Isn't that an ARM chip? The default MMAP handler in ALSA doesn't support ARM, but it works for PowerPC.
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-October/003773.htm...
IOW: have you actually tested that the following commands work (X,Y refer to the FSL chip)?
aplay -M -D hw:X,Y sample.wav arecord -f cd -M -D:X,Y capture.wav
I haven't tried record, but I did try playback, and it worked. Without this patch, adding -M gives me this error:
aplay: set_params:852: Access type not available
After applying this patch, playback works fine.
At Thu, 17 Jan 2008 10:31:37 -0600, Timur Tabi wrote:
Alexander E. Patrakov wrote:
Timur Tabi wrote:
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's default mmap functionality, it was just not enabled previously.
Signed-off-by: Timur Tabi timur@freescale.com
[sorry, I may be completely wrong below about the .page callback purpose
- in this case, just confirm that the testcase works]
Hm, the "struct snd_pcm_ops fsl_dma_ops" doesn't contain the .page callback. With saa7134-alsa, this led to the "device claims to support mmap but actually doesn't work" bug, see the following subthread:
Isn't that an ARM chip? The default MMAP handler in ALSA doesn't support ARM, but it works for PowerPC.
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-October/003773.htm...
IOW: have you actually tested that the following commands work (X,Y refer to the FSL chip)?
aplay -M -D hw:X,Y sample.wav arecord -f cd -M -D:X,Y capture.wav
I haven't tried record, but I did try playback, and it worked. Without this patch, adding -M gives me this error:
aplay: set_params:852: Access type not available
After applying this patch, playback works fine.
Great, applied to ALSA tree now.
Thanks.
Takashi
Timur Tabi wrote:
Alexander E. Patrakov wrote:
Hm, the "struct snd_pcm_ops fsl_dma_ops" doesn't contain the .page callback. With saa7134-alsa, this led to the "device claims to support mmap but actually doesn't work" bug, see the following subthread:
Isn't that an ARM chip? The default MMAP handler in ALSA doesn't support ARM, but it works for PowerPC.
saa7134 is a Philips chip that you'll find in many TV tuners.
As for the .page logic, my question was indeed stupid. I should have read the snd_pcm_mmap_data_nopage() function and notice that, by default, it wants to do this:
vaddr = runtime->dma_area + offset; page = virt_to_page(vaddr);
and saa7134 wants to use vmalloc_to_page() instead of virt_to_page() due to the way it allocates the DMA buffer.
I haven't tried record, but I did try playback, and it worked. Without this patch, adding -M gives me this error:
aplay: set_params:852: Access type not available
After applying this patch, playback works fine.
Good!
On Thu, 17 Jan 2008, Timur Tabi wrote:
Alexander E. Patrakov wrote:
Timur Tabi wrote:
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's default mmap functionality, it was just not enabled previously.
Signed-off-by: Timur Tabi timur@freescale.com
[sorry, I may be completely wrong below about the .page callback purpose
- in this case, just confirm that the testcase works]
Hm, the "struct snd_pcm_ops fsl_dma_ops" doesn't contain the .page callback. With saa7134-alsa, this led to the "device claims to support mmap but actually doesn't work" bug, see the following subthread:
Isn't that an ARM chip? The default MMAP handler in ALSA doesn't support ARM, but it works for PowerPC.
Alexander is talking about the same thing I was in my previous message to you. saa7134, like cx88-alsa, uses vmalloc instead of ALSA to allocate the DMA buffer, and so a special page callback is needed.
I haven't tried record, but I did try playback, and it worked. Without this patch, adding -M gives me this error:
aplay: set_params:852: Access type not available
After applying this patch, playback works fine.
The key thing to know is that you will not get an error message if your page callback is wrong! Everything will appear to work. You just won't hear any sound.
Trent Piepho wrote:
The key thing to know is that you will not get an error message if your page callback is wrong! Everything will appear to work. You just won't hear any sound.
When I said playback works fine, I was wearing my headphones. :-)
participants (4)
-
Alexander E. Patrakov -
Takashi Iwai -
Timur Tabi -
Trent Piepho