[SRU][Xenial][PATCH 0/2] alsa/hdmi: the hdmi audio stops working from Ubuntu-4.4.0-155.182

[Hui Wang]

BugLink: https://bugs.launchpad.net/bugs/1895603

[Impact]
We had a Dell machine, this machine was enabled with ubuntu 4.4
kernel before, but recently the hdmi audio on this machine stopped
working with the latest ubuntu 4.4. kernel. The system can't detect
its plugging and can't output sound to it anymore.

[Fix]
This is because we backported a patch from stable updates, and that
patch is for v5.2 kernel, if we backported it to 4.4 kernel, we need
to do some change, and also we need to backport one more patch from
stabe kernel.

[Test Case]
Connect a monitor to the machine and boot up, after booting up, we
could see the hdmi audio is found, and play sound to the hdmi audio,
we could hear the sound from monitor.


[Regression Risk]
It is possible to make the hdmi audio fail to work after applying this
patchset, like the hdmi audio can't be detected after plugging a hdmi
monitor. But this possibility is very low, we tested the patchset on
many dell and lenovo machines, all worked well.

Hui Wang (2):
  ALSA: hda/hdmi - Read the pin sense from register when repolling
  UBUNTU: SAUNCE: ALSA: hda/hdmi - Check pin_eld->monitor_present

 sound/pci/hda/patch_hdmi.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

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2.17.1