mpc8610: Add mmap support
Subsystems (3)
PATCH 1/1 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.
--- sound/soc/fsl/fsl_dma.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
sound/soc/fsl/fsl_dma.c +3 -1
@@ -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 ,
Signature · 1 line
1.5.2.4
Quoted 4 lines · Timur Tabi
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 <[email protected]>
[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.html
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
Quoted 19 lines
--- sound/soc/fsl/fsl_dma.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)sound/soc/fsl/fsl_dma.c +3
-1@@ -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 ,
Signature · 1 line
Alexander E. Patrakov
Quoted 5 lines · Alexander E. Patrakov
Quoted 4 lines · Timur Tabi
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's
default mmap functionality, it was just not enabled previously.
Quoted 8 lines
Quoted 1 line
Signed-off-by Timur Tabi <[email protected]>[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_opsfsl_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.
Quoted 8 lines
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-October/003773.html
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.
Signature · 2 lines
Timur Tabi Linux kernel developer at Freescale
At Thu, 17 Jan 2008 10:31:37 -0600,
Quoted 28 lines · Timur Tabi
Quoted 5 lines · Alexander E. Patrakov
Quoted 4 lines · Timur Tabi
Enable mmap support in the MPC8610 ASoC driver. The driver can use ALSA's
default mmap functionality, it was just not enabled previously.Quoted 8 lines
Quoted 1 line
Signed-off-by Timur Tabi <[email protected]>[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_opsfsl_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.
Quoted 8 lines
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-October/003773.html
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
Quoted 6 lines
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
Quoted 7 lines · Timur Tabi
Quoted 3 lines · Alexander E. Patrakov
Hm, the "struct
snd_pcm_opsfsl_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.
Quoted 6 lines
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!
Signature · 1 line
Alexander E. Patrakov
Quoted 11 lines · Timur Tabi
Quoted 10 lines · Alexander E. Patrakov
Quoted 5 lines · Timur Tabi
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 <[email protected]>[sorry, I may be completely wrong below about the .page callback purpose
- in this case, just confirm that the testcase works]
Quoted 6 lines
Quoted 3 lines
Hm, the "struct
snd_pcm_opsfsl_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.
Quoted 6 lines
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.
Quoted 3 lines · Trent Piepho
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. :-)
Signature · 2 lines
Timur Tabi Linux kernel developer at Freescale