• Phil Calvin's avatar
    ALSA: hda/realtek: fix mic boost on Intel NUC 8 · d1ee66c5
    Phil Calvin authored
    Fix two bugs with the Intel HDA Realtek ALC233 sound codec
    present in Intel NUC NUC8i7BEH and probably a few other similar
    NUC models.
    
    These codecs advertise a 4-level microphone input boost amplifier on
    pin 0x19, but the highest two boost settings do not work correctly,
    and produce only low analog noise that does not seem to contain any
    discernible signal. There is an existing fixup for this exact problem
    but for a different PCI subsystem ID, so we re-use that logic.
    
    Changing the boost level also triggers a DC spike in the input signal
    that bleeds off over about a second and overwhelms any input during
    that time. Thankfully, the existing fixup has the side effect of
    making the boost control show up in userspace as a mute/unmute switch,
    and this keeps (e.g.) PulseAudio from fiddling with it during normal
    input volume adjustments.
    
    Finally, the NUC hardware has built-in inverted stereo mics. This
    patch also enables the usual fixup for this so the two channels cancel
    noise instead of the actual signal.
    
    [ Re-ordered the quirk entry point by tiwai ]
    Signed-off-by: default avatarPhil Calvin <phil@philcalvin.com>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/80dc5663-7734-e7e5-25ef-15b5df24511a@philcalvin.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    d1ee66c5
patch_realtek.c 322 KB