• Takashi Iwai's avatar
    ALSA: usb-audio: Unify mixer resume and reset_resume procedure · 7b9cf903
    Takashi Iwai authored
    USB-audio driver assumes that the normal resume would preserve the
    device configuration while reset_resume wouldn't, and tries to restore
    the mixer elements only at reset_resume callback.  However, this seems
    too naive, and some devices do behave differently, resetting the
    volume at the normal resume; this resulted in the inconsistent volume
    that surprised users.
    
    This patch changes the mixer resume code to handle both the normal and
    reset resume in the same way, always restoring the original mixer
    element values.  This allows us to unify the both callbacks as well as
    dropping the no longer used reset_resume field, which ends up with a
    good code reduction.
    
    A slight behavior change by this patch is that now we assign
    restore_mixer_value() as the default resume callback, and the function
    is no longer called at reset-resume when the resume callback is
    overridden by the quirk function.  That is, if needed, the quirk
    resume function would have to handle similarly as
    restore_mixer_value() by itself.
    Reported-by: default avatarEn-Shuo Hsu <enshuo@chromium.org>
    Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org>
    Link: https://lore.kernel.org/r/CADDZ45UPsbpAAqP6=ZkTT8BE-yLii4Y7xSDnjK550G2DhQsMew@mail.gmail.com
    Link: https://lore.kernel.org/r/20210910105155.12862-1-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    7b9cf903
card.c 31.5 KB