| Message ID | 1395148837-20850-2-git-send-email-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/18/2014 03:20 PM, Peter Ujfalusi wrote: > We need to place constraint on the period if the read or write AFIFO > is enabled and it is configured for more than one word otherwise > the DMA will fail in buffer configuration where the sizes are not > aligned with the requested FIFO configuration. Oh, I edited the commit message and removed the text related to buffer size but I failed to do that for the commit title :( Mark: Do you want me to resend with fixed commit title?
On 03/18/2014 03:23 PM, Peter Ujfalusi wrote: > On 03/18/2014 03:20 PM, Peter Ujfalusi wrote: >> We need to place constraint on the period if the read or write AFIFO >> is enabled and it is configured for more than one word otherwise >> the DMA will fail in buffer configuration where the sizes are not >> aligned with the requested FIFO configuration. > > Oh, I edited the commit message and removed the text related to buffer size > but I failed to do that for the commit title :( Actually I still have issue with the constraint. If I play a 48KHz sample with mplayer it is fine: Trying preferred audio driver 'alsa', options '[none]' alsa-init: requested format: 48000 Hz, 2 channels, 9 alsa-init: using ALSA 1.0.27.2 alsa-init: setup for 1/2 channel(s) alsa-init: using device default alsa-init: opening device in blocking mode alsa-init: device reopened in blocking mode alsa-init: got buffersize=96000 alsa-init: got period size 1600 alsa: 48000 Hz/2 channels/4 bpf/96000 bytes buffer/Signed 16 bit Little Endian AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample) AO: Description: ALSA-0.9.x-1.x audio output AO: Author: Alex Beregszaszi, Zsolt Barat <joy@streamminister.de> AO: Comment: under development Building audio filter chain for 48000Hz/2ch/s16le -> 48000Hz/2ch/s16le... However if I play 44.1KHz sample with mplayer: Trying preferred audio driver 'alsa', options '[none]' alsa-init: requested format: 44100 Hz, 2 channels, 9 alsa-init: using ALSA 1.0.27.2 alsa-init: setup for 1/2 channel(s) alsa-init: using device default alsa-init: opening device in blocking mode alsa-init: device reopened in blocking mode ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 500000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 44100 PERIOD_TIME: 50000 PERIOD_SIZE: NONE PERIOD_BYTES: [4736 65536] PERIODS: (1 19) BUFFER_TIME: 500000 BUFFER_SIZE: 22050 BUFFER_BYTES: 88200 TICK_TIME: ALL [AO_ALSA] Unable to set buffer time near: Invalid argument Failed to initialize audio driver 'alsa' Now if I place the same constraint to the buffer size as well and playing the same 44.1KHz sample: Trying preferred audio driver 'alsa', options '[none]' alsa-init: requested format: 44100 Hz, 2 channels, 9 alsa-init: using ALSA 1.0.27.2 alsa-init: setup for 1/2 channel(s) alsa-init: using device default alsa-init: opening device in blocking mode alsa-init: device reopened in blocking mode alsa-init: got buffersize=88192 alsa-init: got period size 1696 alsa: 44100 Hz/2 channels/4 bpf/88192 bytes buffer/Signed 16 bit Little Endian AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample) AO: Description: ALSA-0.9.x-1.x audio output AO: Author: Alex Beregszaszi, Zsolt Barat <joy@streamminister.de> AO: Comment: under development Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le... It seams that I need to place the same constraint step to both period size and buffer size. For some reason snd_pcm_hw_params_set_buffer_time_near() fails in case of 44.1KHz when asking for 0.5s buffer when I placed step 32 constraint to period size. Placing the same 32 steps constraint to the buffer size as well will make things working (for mplayer at least)
On Tue, Mar 18, 2014 at 04:28:55PM +0200, Peter Ujfalusi wrote: > On 03/18/2014 03:23 PM, Peter Ujfalusi wrote: > > Oh, I edited the commit message and removed the text related to buffer size > > but I failed to do that for the commit title :( > Actually I still have issue with the constraint. OK, so is the patch an improvement or not? If it fixes some cases it's probably worth applying even if further fixes are still needed. No need to resend for the subject, I can fix that up. > It seams that I need to place the same constraint step to both period size and > buffer size. > For some reason snd_pcm_hw_params_set_buffer_time_near() fails in case of > 44.1KHz when asking for 0.5s buffer when I placed step 32 constraint to period > size. Placing the same 32 steps constraint to the buffer size as well will > make things working (for mplayer at least) That seems like the constraint code is failing, at a guess probably looking for too near a value of near if you see what I mean. I don't really have the time/enthusiasm to investigate this right now, sorry.
On 03/18/2014 08:07 PM, Mark Brown wrote: > On Tue, Mar 18, 2014 at 04:28:55PM +0200, Peter Ujfalusi wrote: >> On 03/18/2014 03:23 PM, Peter Ujfalusi wrote: > >>> Oh, I edited the commit message and removed the text related to buffer size >>> but I failed to do that for the commit title :( > >> Actually I still have issue with the constraint. > > OK, so is the patch an improvement or not? If it fixes some cases it's > probably worth applying even if further fixes are still needed. Some application might fail (like mplayer with 44.1KHz) with constraint on the period size only. Without the constraint we will have constant pops at every period when non aligned size has been selected - if the FIFO depth is configured to more than 1, which is not yet the case in upstream. > No need to resend for the subject, I can fix that up. > >> It seams that I need to place the same constraint step to both period size and >> buffer size. >> For some reason snd_pcm_hw_params_set_buffer_time_near() fails in case of >> 44.1KHz when asking for 0.5s buffer when I placed step 32 constraint to period >> size. Placing the same 32 steps constraint to the buffer size as well will >> make things working (for mplayer at least) > > That seems like the constraint code is failing, at a guess probably > looking for too near a value of near if you see what I mean. I don't > really have the time/enthusiasm to investigate this right now, sorry. Yep, this needs to be investigated. Me or Jyri will take a look at this for sure since it is somehow odd.
On Wed, Mar 19, 2014 at 01:13:50PM +0200, Peter Ujfalusi wrote: > On 03/18/2014 08:07 PM, Mark Brown wrote: > > OK, so is the patch an improvement or not? If it fixes some cases it's > > probably worth applying even if further fixes are still needed. > Some application might fail (like mplayer with 44.1KHz) with constraint on the > period size only. Without the constraint we will have constant pops at every > period when non aligned size has been selected - if the FIFO depth is > configured to more than 1, which is not yet the case in upstream. OK, given that the FIFO depth change isn't yet upstream it'd be a step backwards so I'll leave this for now.
Hi Mark, On 03/19/2014 03:14 PM, Mark Brown wrote: > On Wed, Mar 19, 2014 at 01:13:50PM +0200, Peter Ujfalusi wrote: >> On 03/18/2014 08:07 PM, Mark Brown wrote: > >>> OK, so is the patch an improvement or not? If it fixes some cases it's >>> probably worth applying even if further fixes are still needed. > >> Some application might fail (like mplayer with 44.1KHz) with constraint on the >> period size only. Without the constraint we will have constant pops at every >> period when non aligned size has been selected - if the FIFO depth is >> configured to more than 1, which is not yet the case in upstream. > > OK, given that the FIFO depth change isn't yet upstream it'd be a step > backwards so I'll leave this for now. I have looked at the issue and I found some clues on why mplayer fails: it try to set the snd_pcm_hw_params_set_buffer_time_near() first followed by the snd_pcm_hw_params_set_periods_near(). And this fails in some cases when we have constraint step on the period only. Other applications set the period param first followed by the buffer (aplay and various alsa test tools as well). PA however have a fallback mechanism: 1. buffer first followed by period 2. period first followed by buffer 3. buffer only 4. period only 5. no period, no buffer params When I have step constraint on period PA fails with the first, second (because there's a bug in the PA code here) and third method but going to succeed with four. I have looked around in the kernel and other drivers do set both period and buffer step constraint, for example: sound/arm/pxa2xx-pcm-lib.c (_BYTES) sound/drivers/vx/vx_pcm.c (_BYTES) sound/pci/echoaudio/echoaudio.c (_SIZE) sound/pci/ice1712/ice1724.c (_BYTES) sound/pci/lola/lola_pcm.c (_SIZE) sound/soc/kirkwood/kirkwood-dma.c (_BYTES) sound/soc/s6000/s6000-pcm.c (_BYTES) ... I still don't know why buffer size fails (in some cases) if we only have step constraint on the period size, but it looks to me that others also encountered with similar issues and the fix they have is the same what I had in the first version of the patch.
On 03/20/2014 02:47 PM, Peter Ujfalusi wrote: > Hi Mark, > > On 03/19/2014 03:14 PM, Mark Brown wrote: >> On Wed, Mar 19, 2014 at 01:13:50PM +0200, Peter Ujfalusi wrote: >>> On 03/18/2014 08:07 PM, Mark Brown wrote: >> >>>> OK, so is the patch an improvement or not? If it fixes some cases it's >>>> probably worth applying even if further fixes are still needed. >> >>> Some application might fail (like mplayer with 44.1KHz) with constraint on the >>> period size only. Without the constraint we will have constant pops at every >>> period when non aligned size has been selected - if the FIFO depth is >>> configured to more than 1, which is not yet the case in upstream. >> >> OK, given that the FIFO depth change isn't yet upstream it'd be a step >> backwards so I'll leave this for now. > > I have looked at the issue and I found some clues on why mplayer fails: > it try to set the snd_pcm_hw_params_set_buffer_time_near() first followed by > the snd_pcm_hw_params_set_periods_near(). And this fails in some cases when we > have constraint step on the period only. > Other applications set the period param first followed by the buffer (aplay > and various alsa test tools as well). > PA however have a fallback mechanism: > 1. buffer first followed by period > 2. period first followed by buffer > 3. buffer only > 4. period only > 5. no period, no buffer params > > When I have step constraint on period PA fails with the first, second (because > there's a bug in the PA code here) and third method but going to succeed with > four. > > I have looked around in the kernel and other drivers do set both period and > buffer step constraint, for example: > > sound/arm/pxa2xx-pcm-lib.c (_BYTES) > sound/drivers/vx/vx_pcm.c (_BYTES) > sound/pci/echoaudio/echoaudio.c (_SIZE) > sound/pci/ice1712/ice1724.c (_BYTES) > sound/pci/lola/lola_pcm.c (_SIZE) > sound/soc/kirkwood/kirkwood-dma.c (_BYTES) > sound/soc/s6000/s6000-pcm.c (_BYTES) > ... > > I still don't know why buffer size fails (in some cases) if we only have step > constraint on the period size, but it looks to me that others also encountered > with similar issues and the fix they have is the same what I had in the first > version of the patch. That sounds like a bug in either the kernel or alsa-lib. We do have a rule in place that specifies that the buffer size needs to be a integer multiple of the period size and we have a rule in place that the period size needs to be a multiple of a constant C. Hence ALSA should be able to deduce that the buffer size needs to be at least a multiple of min_periods * C. We probably should fix this for good and not workaround it in individual drivers. Do you think you can put together a small standalone test application that shows the issue? - Lars
On 03/20/2014 04:15 PM, Lars-Peter Clausen wrote: > That sounds like a bug in either the kernel or alsa-lib. We do have a rule in > place that specifies that the buffer size needs to be a integer multiple of > the period size and we have a rule in place that the period size needs to be a > multiple of a constant C. Hence ALSA should be able to deduce that the buffer > size needs to be at least a multiple of min_periods * C. We probably should > fix this for good and not workaround it in individual drivers. Do you think > you can put together a small standalone test application that shows the issue? Now that I have 'wasted' quite some time with this I ended up writing the tool to test the issue. It is a simple tool which: opens the hw:0,0 (you can pass another PCM to open). Goes and tests 44.1, 88.2, 48 and 96 KHz from 0.1s to 1s buffer time with 0.005s steps. It prints the running test and tells if the combination failed or not. If it is OK, it is going to print the resulting buffer time. Since the output is long for email they are in pastebin. On am335x-evmsk only period_step = 32 constraint is placed by the McASP driver: http://pastebin.com/C81uQkJd When both period_step and buffer_step is set to 32: http://pastebin.com/D8hr3bQ1 As a note: if I run this tool on my desktop/laptop it does fail in some combination there as well with hd_intel. What is even more interesting is that I have less failure cases with hda_intel on 64bit machines then on my old macbook1,1 which is 32bit Linux. Basically the mcabook,1,1 behaves similarly like my am335x (when I change the hda_intel driver to place only period_step = 32 constraint)
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c index a01ae97c90aa..df067a836c4d 100644 --- a/sound/soc/davinci/davinci-mcasp.c +++ b/sound/soc/davinci/davinci-mcasp.c @@ -720,6 +720,7 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai); + int afifo_numevt; if (mcasp->version == MCASP_VERSION_4) snd_soc_dai_set_dma_data(dai, substream, @@ -727,6 +728,16 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream, else snd_soc_dai_set_dma_data(dai, substream, mcasp->dma_params); + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + afifo_numevt = mcasp->txnumevt; + else + afifo_numevt = mcasp->rxnumevt; + + if (afifo_numevt > 1) + snd_pcm_hw_constraint_step(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, + afifo_numevt); + return 0; }
We need to place constraint on the period if the read or write AFIFO is enabled and it is configured for more than one word otherwise the DMA will fail in buffer configuration where the sizes are not aligned with the requested FIFO configuration. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> --- sound/soc/davinci/davinci-mcasp.c | 11 +++++++++++ 1 file changed, 11 insertions(+)