mbox series

[SRU,OEM-5.6,0/1] Fix suspend error of SOF driver

Message ID 20201218130403.33270-1-kai.heng.feng@canonical.com
Headers show
Series Fix suspend error of SOF driver | expand

Message

Kai-Heng Feng Dec. 18, 2020, 1:04 p.m. UTC 
BugLink: https://bugs.launchpad.net/bugs/1908713

[Impact]
SOF driver in oem-5.6 kernel tries to access HDA codec register when the
codec is already suspended. This may freeze suspend.

[Fix]
Revert HDA codec PM direct-complete optimization.
The same suspend optimization works perfectly on 5.8 and 5.10 kernel, so
something's wrong in the SOF driver in oem-5.6. However, SOF in oem-5.6
is in Frankenstein state so we better not touch it.

[Test]
Suspend a laptop with SOF driver, it can take 30 seconds to suspend, or
worse, it freezes.

With the patch applied, it can suspend in 1 second.

[Regression Risk]
For HDA codecs that benefit from this PM optimization, it'll take longer
to suspend and resume. Nothing else changes other than that.

Kai-Heng Feng (1):
  Revert "ALSA: hda: Refactor codec PM to use direct-complete
    optimization"

 sound/pci/hda/hda_codec.c | 45 ++++++++++++++-------------------------
 1 file changed, 16 insertions(+), 29 deletions(-)