On Tue, Nov 19, 2019 at 12:12:35PM +0100, Hans de Goede wrote:
> On 19-11-2019 09:26, Mika Westerberg wrote:
> > On Mon, Nov 18, 2019 at 04:35:56PM +0100, Hans de Goede wrote:
> Working around this is not impossible, but it will be quite ugly and given
> the age of the machine IMHO not worth it. I've also found out that I need a
> DSDT override to be able to control the LCD backlight, this is controlled by
> the 1st PWM controller in the SoC LPSS block, which is normally enumerated
> through ACPI but the entire Device (PWM1) {} block is missing from the
> DSDT :| Adding it from similar hardware fixes things and makes the backlight
> controllable. TL;DR: it seems that this is one of the rare cased where
> people who want to run Linux will need to do a manual DSDT override :|
If it's missing it's easy to inject entire block from EFI variable or using
ConfigFS (see meta-acpi project [1] for details).
> When they do that override they can also fix the _LID method and
> then re-enable LID functionality on the kernel commandline overriding
> this DMI quirk.
Yes, if you override entire DSDT it can be fixed for many bugs at once.
> I will probably do a blog post on this (some people have asked me
> to do some blogposts about how to analyze DSDT-s, this will be a nice
> example) and add a link to the DSDT override to the blogpost, I believe
> that this is the best we can do for users of this device.
Perhaps above mentioned project somehow can be extended to keep DSDT ASL code
for overriding? Mika?
[1]: https://github.com/westeri/meta-acpi/
--
With Best Regards,
Andy Shevchenko
