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* missing sound on kernel-5.15
@ 2022-08-22  8:06 chihhao chen
  2022-08-22 11:57 ` Geraldo Nascimento
  0 siblings, 1 reply; 28+ messages in thread
From: chihhao chen @ 2022-08-22  8:06 UTC (permalink / raw)
  To: alsa-devel; +Cc: chihhao.chen

I am testing many headsets on Android platform with different kernel
versions.

On kernel-5.10, calling sequence for playback is
1. snd_usb_hw_params -> set highest sampling rate, no
SAMPLING_FREQ_CONTROL USB request sent in this stage
2. snd_pcm_release
3. snd_usb_hw_params -> set proper sampling rate, still no
SAMPLING_FREQ_CONTROL USB request 
4. snd_usb_pcm_parepare -> in configure_endpoint SAMPLING_FREQ_CONTROL
USB request was sent on USB bus

With the same calling sequence, a slightly behavior change on kernel-
5.15 is
1. snd_usb_hw_params -> set highest sampling rate,
SAMPLING_FREQ_CONTROL USB request  was sent on USB bus
2. snd_pcm_release
3. snd_usb_hw_params -> set proper sampling rate, SAMPLING_FREQ_CONTROL
USB request  was sent too
(because configure_endpoint was moved to snd_usb_hw_params function)
4. snd_usb_pcm_parepare -> no SAMPLING_FREQ_CONTROL USB
request  because of USB EP flag check

I checked all USB packets and confirmed audio data output was correct.
But there may be missing sound problem for the first sound with many
headsets (for example Samsung headset).
I found this issue is related to two-times sampling rate set request.
(I tried to forcibly skip first USB request, everything became okay.)
So do you guys know why configure_endpoint was moved to
snd_usb_hw_params?
Or could you provide patch for this problem?

Many thanks
Chihhao


^ permalink raw reply	[flat|nested] 28+ messages in thread
[parent not found: <1661150747490509987-webhooks-bot@alsa-project.org>]

end of thread, other threads:[~2022-11-11  7:59 UTC | newest]

Thread overview: 28+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-22  8:06 missing sound on kernel-5.15 chihhao chen
2022-08-22 11:57 ` Geraldo Nascimento
2022-08-29  7:56   ` chihhao chen
2022-08-29  8:06     ` Takashi Iwai
2022-08-29  8:50       ` chihhao chen
2022-08-29 12:16         ` Takashi Iwai
2022-08-29 18:15           ` Takashi Iwai
2022-08-30  5:54             ` Takashi Iwai
2022-08-30  6:02               ` Takashi Iwai
2022-08-30  6:13               ` chihhao chen
2022-08-30  7:02                 ` Takashi Iwai
2022-08-30  8:08                   ` chihhao chen
2022-08-30  8:24                     ` Takashi Iwai
2022-08-31  3:39                       ` chihhao chen
2022-08-31  5:18                         ` Takashi Iwai
2022-08-31  7:03                           ` chihhao chen
2022-08-31  8:04                             ` Takashi Iwai
2022-08-31  9:26                               ` chihhao chen
2022-08-31 10:48                                 ` Takashi Iwai
2022-08-31 13:16                                   ` chihhao chen
2022-08-31 13:40                                     ` Takashi Iwai
2022-09-01  5:50                                       ` chihhao chen
2022-09-01  7:51                                         ` Takashi Iwai
2022-09-01  8:28                                           ` Takashi Iwai
2022-09-01 10:06                                             ` chihhao chen
2022-09-01 10:25                                               ` Takashi Iwai
2022-11-11  7:58                                                 ` Chihhao Chen (陳志豪)
     [not found] <1661150747490509987-webhooks-bot@alsa-project.org>
2022-08-22  6:45 ` GitHub issues - opened

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