From: Takashi Iwai <tiwai@xxxxxxx> commit d2e8f641257d0d3af6e45d6ac2d6f9d56b8ea964 upstream. In the current code, we have some assumption that the audio clock selector has been set up implicitly and don't want to touch it unless it's really needed for the fallback autoclock setup. This works for most devices but some seem having a problem. Partially this was covered for the devices with a single connector at the initialization phase (commit 086b957cc17f "ALSA: usb-audio: Skip the clock selector inquiry for single connections"), but also there are cases where the wrong clock set up is kept silently. The latter seems to be the cause of the noises on Behringer devices. In this patch, we explicitly set up the audio clock selector whenever the appropriate node is found. Reported-by: Geraldo Nascimento <geraldogabriel@xxxxxxxxx> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199327 Link: https://lore.kernel.org/r/CAEsQvcvF7LnO8PxyyCxuRCx=7jNeSCvFAd-+dE0g_rd1rOxxdw@xxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210413084152.32325-1-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/usb/clock.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -296,7 +296,7 @@ static int __uac_clock_find_source(struc selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); if (selector) { - int ret, i, cur; + int ret, i, cur, err; /* the entity ID we are looking for is a selector. * find out what it currently selects */ @@ -318,13 +318,17 @@ static int __uac_clock_find_source(struc ret = __uac_clock_find_source(chip, fmt, selector->baCSourceID[ret - 1], visited, validate); + if (ret > 0) { + err = uac_clock_selector_set_val(chip, entity_id, cur); + if (err < 0) + return err; + } + if (!validate || ret > 0 || !chip->autoclock) return ret; /* The current clock source is invalid, try others. */ for (i = 1; i <= selector->bNrInPins; i++) { - int err; - if (i == cur) continue; @@ -390,7 +394,7 @@ static int __uac3_clock_find_source(stru selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id); if (selector) { - int ret, i, cur; + int ret, i, cur, err; /* the entity ID we are looking for is a selector. * find out what it currently selects */ @@ -412,6 +416,12 @@ static int __uac3_clock_find_source(stru ret = __uac3_clock_find_source(chip, fmt, selector->baCSourceID[ret - 1], visited, validate); + if (ret > 0) { + err = uac_clock_selector_set_val(chip, entity_id, cur); + if (err < 0) + return err; + } + if (!validate || ret > 0 || !chip->autoclock) return ret;
