[alsa-devel] [PATCH 2/4] acpi: allow for an override to set _REV

[Rafael J. Wysocki]

On Thursday, May 21, 2015 01:18:44 PM Mario Limonciello wrote:
> 
> On 05/21/2015 01:10 PM, Matthew Garrett wrote:
> > On Wed, May 20, 2015 at 6:24 PM, Rafael J. Wysocki <rjw at rjwysocki.net> wrote:
> >
> >> Which doesn't explain why we need a config option per quirk.  To me, such config
> >> options don't add any value, because (a) everyone will set them anyway and (b)
> >> removing the quirks from the source is trivial if needed.
> > We'd disable this quirk in Fedora the moment jack detection works,
> > because we've got the userspace to handle it and using I2S is
> > preferable to using HDA - but in doing so we might break battery
> > detection on the other Dell that's playing _REV tricks. This seems
> > like a suboptimal choice to have to make.
> 
> Having dug into this deeper with you on the other thread, battery 
> detection already wasn't working.
> That machine did the _REV test and fix for Linux only on Windows 2009 
> _OSI and the _REV value of 5.
> The kernel currently responds to a later _OSI that the machine supports 
> so that AML does not get run.
> 
> I believe battery detection may be fixed on that Inspiron by 
> 75646e758a0ecbed5024454507d5be5b9ea9dcbf.
> if it's not, that's a tangential problem that should be fixed to match 
> the Windows behavior for battery detection.

OK, so do we have any proof that anything in addition to the sound thing
is broken by returning 2 from _REV?

If not, then we're probably spending too much time discussing this.


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.