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

[Jani Nikula]

On Wed, 06 Jan 2021, Imre Deak <imre.deak at intel.com> wrote:
> On Tue, Jan 05, 2021 at 05:50:41AM +0000, Matthew Wilcox wrote:
>> 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!
>
> Thanks for testing it, I'll send a patch for the 5.10 stable tree as
> well.
>
>> 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?
>
> One possibility is that from the different backlight methods (DPCD,
> direct PWM on a CPU pin) the driver selects the incorrect one. Could you
> provide a log booting with drm.debug=0x1e adding it to a new ticket at
>
> https://gitlab.freedesktop.org/drm/intel/-/issues/new?issue
>
> or at least in a reply to this thread?
>
> Adding Jani for further ideas.

Please try:

1) i915.enable_dpcd_backlight=1 module param

2) https://cgit.freedesktop.org/drm/drm-tip drm-tip branch with patches
   from Lyude on top https://patchwork.freedesktop.org/series/81702/

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center