]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/commit - sound/pci/hda/hda_intel.c
ALSA: hda - Force polling mode on CFL for fixing codec communication
authorTakashi Iwai <tiwai@suse.de>
Mon, 26 Mar 2018 06:37:00 +0000 (08:37 +0200)
committerKleber Sacilotto de Souza <kleber.souza@canonical.com>
Thu, 29 Mar 2018 16:16:25 +0000 (18:16 +0200)
commit9ae118dbbe7bcd13fa29a441f932c2694f7925e2
tree3971ca45ab27d1dfec881f2f9a200a2258e4842e
parent8228e45c8e47fe302ef5fb132b227855b4f612a5
ALSA: hda - Force polling mode on CFL for fixing codec communication

BugLink: https://bugs.launchpad.net/bugs/1758800
We've observed too long probe time with Coffee Lake (CFL) machines,
and the likely cause is some communication problem between the
HD-audio controller and the codec chips.  While the controller expects
an IRQ wakeup for each codec response, it seems sometimes missing, and
it takes one second for the controller driver to time out and read the
response in the polling mode.

Although we aren't sure about the real culprit yet, in this patch, we
put a workaround by forcing the polling mode as default for CFL
machines; the polling mode itself isn't too heavy, and much better
than other workarounds initially suggested (e.g. disabling
power-save), at least.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199007
Fixes: e79b0006c45c ("ALSA: hda - Add Coffelake PCI ID")
Reported-and-tested-by: Hui Wang <hui.wang@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
(cherry picked from commit a8d7bde23e7130686b76624b099f3e22dd38aef7)
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Acked-by: Aaron Ma <aaron.ma@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
sound/pci/hda/hda_intel.c