On Sun, Dec 11, 2022 at 04:30:11PM +0100, Ruud van Asseldonk wrote: > Hi all, > > This issue is still present in 5.15.82, is there anything I can do to > diagnose this further? Hi Ruud, Sorry for your troubles. You could use "git bisect" to try to pinpoint the exact commit that introduces failure for you. Thanks, Geraldo Nascimento > > Best, > > Ruud van Asseldonk > > > Hi, > > > > I have a program that configures a Behringer UMC404HD 192k USB audio > > interface for playback as follows (pseudocode): > > > > snd_pcm_hw_params_set_channels(pcm, hwp, 2); > > snd_pcm_hw_params_set_format(pcm, hwp, SND_PCM_FORMAT_S24_3LE); > > snd_pcm_hw_params_set_access(pcm, hwp, SND_PCM_ACCESS_MMAP_INTERLEAVED); > > snd_pcm_hw_params_set_rate(pcm, hwp, val=96000, dir=0); > > snd_pcm_hw_params_set_period_size_near(pcm, hwp, val=513, dir=0); > > // If I confirm at this point with snd_pcm_hw_params_get_period_size, > > // I get back 513. > > snd_pcm_hw_params_set_buffer_size_near(pcm, hwp, val=2052); > > snd_pcm_hw_params(pcm, hwp); > > // If I confirm with snd_pcm_hw_params_get_buffer_size, > > // I get back 2052. > > > > On Linux 5.10.94 (specifically Arch Linux ARM package > > linux-rpi-5.10.94-1), this succeeds, and I can play back audio just > > fine. On 5.15.21 (specifically linux-rpi-5.15.21-3), all the calls > > succeed apart from the last one, which returns EINVAL. > > > > (My actual program is written in Rust and uses a Rust wrapper library > > for libasound, https://docs.rs/alsa/0.6.0/alsa/, but the calls should be > > the ones listed.) > > > > I confirmed with snd_pcm_hw_params_test_format that the S24_3LE format > > is supported. On both kernels it is successful. I confirmed with > > snd_pcm_hw_params_test_rate that 96 kHz is supported. On both kernels it > > is successful. There are differences though. When I query these: > > > > snd_pcm_hw_params_get_period_size_min > > snd_pcm_hw_params_get_period_size_max > > snd_pcm_hw_params_get_buffer_size_min > > snd_pcm_hw_params_get_buffer_size_max > > > > Then on 5.10.94 (the good version), I get: > > > > period size min/max: 12/32768, buffer size min/max: 24/65536 > > > > But on 5.15.21 (the bad version), I get: > > > > period size min/max: 13/71332, buffer size min/max: 26/142663 > > > > Also, after I set the period size to 513, if I then query the buffer > > size min/max, on 5.10.94 I get: > > > > buffer size min/max: 1026/65536 > > > > But on 5.15.21 I get: > > > > buffer size min/max: 1027/142663 > > > > In lsmod, snd_usb_audio shows up, and from lsusb -v, the UMC404HD > > appears to be a standard USB audio interface. The lsusb output is > > identical on both kernels. > > > > Please let me know if there is anything I can do to help further > > diagnose the issue, or if I should report this elsewhere. > > > > Kind regards, > > Ruud van Asseldonk
