[alsa-devel] [RFC v3] ALSA: hda: Add a power_save blacklist

[Takashi Iwai]

On Fri, 23 Feb 2018 08:16:01 +0100,
Hans de Goede wrote:
> 
> Hi,
> 
> On 22-02-18 14:20, Hans de Goede wrote:
> > On some boards setting power_save to a non 0 value leads to clicking /
> > popping sounds when ever we enter/leave powersaving mode. Ideally we would
> > figure out how to avoid these sounds, but that is not always feasible.
> >
> > This commit adds a blacklist for devices where powersaving is known to
> > cause problems and disables it on these devices.
> >
> > Note I tried to put this blacklist in userspace first:
> > https://github.com/systemd/systemd/pull/8128
> >
> > But the systemd maintainers rightfully pointed out that it would be
> > impossible to then later remove entries once we actually find a way to
> > make power-saving work on listed boards without issues. Having this list
> > in the kernel will allow removal of the blacklist entry in the same commit
> > which fixes the clicks / plops.
> >
> > The blacklist only applies to the default power_save module-option value,
> > if a user explicitly sets the module-option then the blacklist is not
> > used.
> >
> > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1525104
> > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=198611
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> 
> This has been tested now, so this may be applied now,
> assuming people are happy with this version.
> 
> Let me know if you want me to re-submit as a non-RFC.

I applied it now, thanks.


Takashi