[Intel-gfx] Missing DPPLL case on i7-1165G7

[Matthew Wilcox]

On Tue, Dec 29, 2020 at 04:41:31PM +0200, Imre Deak wrote:
> Hi,
> 
> On Mon, Dec 21, 2020 at 04:07:58AM +0000, Matthew Wilcox wrote:
> > 
> > At boot,
> > 
> > [    2.787995] [drm:lspcon_init [i915]] *ERROR* Failed to probe lspcon
> > [    2.788001] i915 0000:00:02.0: [drm] *ERROR* LSPCON init failed on port E
> > [    2.790752] ------------[ cut here ]------------
> > [    2.790753] Missing case (clock == 539440)
> > [    2.790790] WARNING: CPU: 0 PID: 159 at drivers/gpu/drm/i915/display/intel_dpll_mgr.c:2967 icl_get_dplls+0x53a/0xa50 [i915]
> 
> the above warn looks to be due to a missing workaround fixed by
> 
> commit 0e2497e334de42dbaaee8e325241b5b5b34ede7e
> Author: Imre Deak <imre.deak at intel.com>
> Date:   Sat Oct 3 03:18:46 2020 +0300
> 
>     drm/i915/tgl: Fix Combo PHY DPLL fractional divider for 38.4MHz ref clock
> 
> in drm-tip. Could you give it a try?

I tried -rc2, which contains that commit, and the problem is gone.  Thank
you!

There is a different problem, which is that the brightness buttons
(on F2 and F3 on this laptop) do not actually increase/decrease the
brightness.  GNOME pops up a graphic that illustrates it is changing
the brightness, but nothing actually changes.

xbacklight says "No outputs have backlight property" and using
xrandr --output XWAYLAND0 --brightness 0.0001 doesn't change anything
(for various different values, not just 0.0001).  Using xrandr --prop
--verbose shows the reported value of "Brightness" changing, but nothing
has changed on the screen.

I found
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight
and tried setting 'brightness' in there to a few different values (100,
2000, 19200, 7000) and also nothing changed.

Any thoughts?