• Takashi Iwai's avatar
    ALSA: hda - Apply sync-write workaround to old Intel platforms, too · c366b3db
    Takashi Iwai authored
    Klaus Ethgen reported occasional high CPU usages in his system that
    seem caused by HD-audio driver.  The perf output revealed that it's
    in the unsolicited event handling in the workqueue, and the problem
    seems triggered by some communication stall between the controller and
    the codec at the runtime or system resume.
    
    Actually a similar phenomenon was seen in the past for other Intel
    platforms, and we already applied the workaround to enforce sync-write
    for CORB/RIRB verbs for Skylake and newer chipsets (commit
    2756d914 "ALSA: hda - Fix intermittent CORB/RIRB stall on Intel
    chips").  Fortunately, the same workaround is applicable to the old
    chipset, and the experiment showed the positive effect.
    
    Based on the experiment result, this patch enables the sync-write
    workaround for all Intel chipsets.  The only reason I hesitated to
    apply this workaround was about the possibly slightly higher CPU usage.
    But if the lack of sync causes a much severer problem even for quite
    old chip, we should think this would be necessary for all Intel chips.
    Reported-by: default avatarKlaus Ethgen <Klaus@ethgen.ch>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20191223171833.GA17053@chua
    Link: https://lore.kernel.org/r/20191223221816.32572-1-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    c366b3db
hda_intel.c 77 KB