Hello Vincent,
thanks for your reply.
On 07/24/2016 04:19 PM, Vincent Bernat wrote:
❦ 24 juillet 2016 13:45 CEST, Bram Bolder <b...@fd0.org> :
after upgrading the meta package 'linux-image-amd64' from
linux-image-4.5.0-2-amd64
to linux-image-4.6.0-1-amd64 (and rebooting), my laptop screen started to
flicker
annoyingly. At first I thought it was a hardware defect (backlight lamp reaching
its end of life), but booting an Ubuntu or reverting to the 4.5.0-2 does not
show
any flickering. The normal terminals (alt-F1 through alt-F6) do not flicker.
My laptop has seen many generations of Linux images while using 'Debian
testing',
all without problems, so it must be related to this latest kernel version.
I tried a clean installation of SID (i.e. without explicitly configuring xorg),
but it reproduces the flickering.
Is /sys/module/i915/parameters/enable_psr set to 1? If yes, can you try
to set it to 0 and check if the problem goes away (no need to restart
anything).
It was set to 1, changing it to 0 did not solve the problem (I stopped xdm,
set the 0 and started it again).
I did some further checking (kernel 4.5 has enable_psr=0 as default). I also
noticed that producing load removed the flickering (e.g. glxgears). It's
definitively
a power saving feature.
I then tried to set i915.enable_psr=0 as commandline option in grub and this
solved
my problem! Hooray!
My question now is how to proceed with this problem. I'm quite sure that you
don't want
everyone with my (or a similar) hardware setup to file a bugreport to you.
Maybe this
problem gets fixes upstream at some point...
Do you want to close this ticket? The problem is solved for me, but maybe other
users
might experience the same problem.
Thanks for your help,
Bram
