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| author | Pavel Hofman <pavel.hofman@ivitera.com> | 2022-01-21 16:53:05 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-26 14:06:09 +0100 |
| commit | 8fe9a03f43316cd93e753d06372159d23ba931d4 (patch) | |
| tree | 4237b4778f1324c1c78a17569786f050002048cb /kernel/module.c | |
| parent | 695d39ffc2b59b8333ff85724619514f98613205 (diff) | |
| download | linux-8fe9a03f43316cd93e753d06372159d23ba931d4.tar.bz2 | |
usb: gadget: u_audio: Rate ctl notifies about current srate (0=stopped)
The Playback/Capture ctl currently reports rate value set by USB
control selector UAC2_CS_CONTROL_SAM_FREQ (fixed for UAC1). When the
stops playback/capture, the reported value does not change. The gadget
side has no information whether the host has started/stopped
capture/playback.
This patch sets the value reported by the respective rate ctl to zero
when the host side has stopped playback/capture. Also, it calls
snd_ctl_notify when start/stop occurs, so that a subscribed client can
act appropriately.
Tests have confirmed that USB hosts change UAC2_CS_CONTROL_SAM_FREQ
before switching altsetting to activate playback/capture, resulting in
correct order (params->c/p_srate is set to requested rate before
u_audio_start_capture/playback is called).
The gadget rate notifications are used by user-space audio gadget
controller gaudio_ctl https://github.com/pavhofman/gaudio_ctl.
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
Link: https://lore.kernel.org/r/20220121155308.48794-8-pavel.hofman@ivitera.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/module.c')
0 files changed, 0 insertions, 0 deletions