• Takashi Iwai's avatar
    ALSA: hda/realtek - Fix speaker output regression on Thinkpad T570 · 54947cd6
    Takashi Iwai authored
    We've got a regression report for some Thinkpad models (at least
    T570s) which shows the too low speaker output volume.  The bisection
    leaded to the commit 61fcf8ec ("ALSA: hda/realtek - Enable Thinkpad
    Dock device for ALC298 platform"), and it's basically adding the two
    pin configurations for the dock, and looks harmless.
    
    The real culprit seems, though, that the DAC assignment for the
    speaker pin is implicitly assumed on these devices, i.e. pin NID 0x14
    to be coupled with DAC NID 0x03.  When more pins are configured by the
    commit above, the auto-parser changes the DAC assignment, and this
    resulted in the regression.
    
    As a workaround, just provide the fixed pin / DAC mapping table for
    this Thinkpad fixup function.  It's no generic solution, but the
    problem itself is pretty much device-specific, so must be good
    enough.
    
    Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1554304
    Fixes: 61fcf8ec ("ALSA: hda/realtek - Enable Thinkpad Dock device for ALC298 platform")
    Cc: <stable@vger.kernel.org>
    Reported-and-tested-by: default avatarJeremy Cline <jcline@redhat.com>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    54947cd6
patch_realtek.c 256 KB