| Message ID | 55AE0831.2010206@streamunlimited.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> > I tried to configure alsa device with snd_pcm_set_params function, requested > parameters was: > channel 2, rate: 22050, soft_resample: 1, latency: 50000 The function snd_pcm_set_params does not always succed especially you are using 22050Hz which is 20ms increment Which soc driver ? It is quite difficult to find the soutce by chip name https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc
I am using 'davinci' soc driver with board specific driver. On 23.07.2015 09:19, Raymond Yau wrote: > > > > > > I tried to configure alsa device with snd_pcm_set_params function, > requested > > parameters was: > > channel 2, rate: 22050, soft_resample: 1, latency: 50000 > > The function snd_pcm_set_params does not always succed especially you > are using 22050Hz which is 20ms increment > > Which soc driver ? It is quite difficult to find the soutce by chip name > > https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc >
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote: > > Hallo, > > I tried to configure alsa device with snd_pcm_set_params function, > requested > parameters was: > channel 2, rate: 22050, soft_resample: 1, latency: 50000 > > Function snd_pcm_hw_params_set_buffer_time_near and > snd_pcm_hw_param_set_near > is called with: > min: 50000, max: 50000, mindir: 0, maxdir: -1 > > and input params was: > > ACCESS: RW_INTERLEAVED > FORMAT: S16_LE > SUBFORMAT: STD > SAMPLE_BITS: 16 > FRAME_BITS: 32 > CHANNELS: 2 > RATE: 22050 > PERIOD_TIME: (362 743039) > PERIOD_SIZE: [8 16384] > PERIOD_BYTES: [32 65536] > PERIODS: [2 19] > BUFFER_TIME: (725 1486078) > BUFFER_SIZE: [16 32768] > BUFFER_BYTES: [64 131072] > TICK_TIME: ALL > > unfortunately, this function fails, on function snd_pcm_hw_param_set_first: > > ALSA ERROR hw_params: set_near (BUFFER_TIME) > value = 50000 : Invalid argument > ACCESS: RW_INTERLEAVED > FORMAT: S16_LE > SUBFORMAT: STD > SAMPLE_BITS: 16 > FRAME_BITS: 32 > CHANNELS: 2 > RATE: 22050 > PERIOD_TIME: (4580 5533) > PERIOD_SIZE: NONE > PERIOD_BYTES: [404 488] > PERIODS: 10 > BUFFER_TIME: (50022 50023) > BUFFER_SIZE: 1103 > BUFFER_BYTES: 4412 > TICK_TIME: ALL > > This shouldn't be problem because in snd_pcm_set_params is > snd_pcm_hw_params_set_period_time_near called. > This function should be called with same params as > snd_pcm_hw_params_set_buffer_time_near > but the input params are: > > snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 > hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) > ACCESS: RW_INTERLEAVED > FORMAT: S16_LE > SUBFORMAT: STD > SAMPLE_BITS: 16 > FRAME_BITS: 32 > CHANNELS: 2 > RATE: 22050 > PERIOD_TIME: (4580 5533) > PERIOD_SIZE: NONE > PERIOD_BYTES: [404 488] > PERIODS: 10 > BUFFER_TIME: (50022 50023) > BUFFER_SIZE: 1103 > BUFFER_BYTES: 4412 > TICK_TIME: ALL > > because in snd_pcm_hw_param_set_near is > > if (last) > err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); > else > err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); > if (err < 0) > dump_hw_params(params, "set_near", var, *val, err); > return err; > > and in error part is only debug output and not restore original parameters. > > Environment: > alsa-lib 1.0.27.1 > TI AM335x soc > > Simple fix is attached, but I am not sure if it is correct. Thanks for analysis and patch. It's however rather a bug in snd_pcm_set_params(). There is no guarantee to keep the old value in snd_pcm_set_*(), thus the caller needs to take care of it instead. Takashi
From 6a31c2f854b255b407ce2d52d233db00588d2e40 Mon Sep 17 00:00:00 2001 From: Martin Geier <martin.geier@streamunlimited.com> Date: Mon, 20 Jul 2015 08:59:54 +0200 Subject: [PATCH] restore params if snd_pcm_hw_param_set_near method failed Signed-off-by: Martin Geier <martin.geier@streamunlimited.com> --- pcm_params.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/pcm/pcm_params.c b/src/pcm/pcm_params.c index 0b66e8c..57d98d8 100644 --- a/src/pcm/pcm_params.c +++ b/src/pcm/pcm_params.c @@ -872,8 +872,10 @@ int snd_pcm_hw_param_set_near(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); - if (err < 0) + if (err < 0) { dump_hw_params(params, "set_near", var, *val, err); + *params = save; + } return err; } -- 1.9.1
Hallo, I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000 Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1 and input params was: ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL unfortunately, this function fails, on function snd_pcm_hw_param_set_first: ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are: snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL because in snd_pcm_hw_param_set_near is if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err; and in error part is only debug output and not restore original parameters. Environment: alsa-lib 1.0.27.1 TI AM335x soc Simple fix is attached, but I am not sure if it is correct. BR Martin Geier