Control: retitle 909770 i915: Does not show gdm greeter on eDP: Link Training failed at link rate = 270000, lane count = 2 Control: severity 909770 important Control: reassign 909770 src:linux Control: affects 909770 gdm3
On Wed, 10 Oct 2018 at 13:22:37 +0200, Sergio Villar Senin wrote: > Note that I've reproduced today this very same issue with lightdm as > well, so I guess this is the confirmation that the bug is somewhere > else. Graphics drivers maybe? Yes, this sounds like a graphics driver problem. Summarizing for kernel/graphics maintainers: Original bug report: > Boot the computer, then wait for the login screen (gdm) to appear. > > The background of the plyumouth theme is shown but the list of > users is not there as expected. > > Sometimes I press the power button and the system suspends to > RAM. When resuming then the gdm login screen is there, *but* if I try to > enter any session (GNOME) it does not work. The authentication seems > to succeed but then the screen becomes blank and there is no > possibility to even switch to the terminals via Ctr-Alt-Fx. Logs: https://pastebin.com/PiwQdiR2 and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=909770#17 Most relevant-looking log message: > laptop kernel: [drm:intel_dp_start_link_train [i915]] *ERROR* > [CONNECTOR:71:eDP-1] Link Training failed at link rate = 270000, lane > count = 2 Workaround (presumably suspend/resume retries link training): > BTW I noticed that it is possible to enter the session by following the > next steps: > 1- Boot > 2- Nothing is shown. Press power button to suspend > 3- Resume laptop. gdm is shown > 4- Enter credentials. Succeeds. > 5- Nothing is shown. Press power button to suspend > 6- Resume laptop. GNOME session is opened and working normally Disabling Wayland in gdm does not work around this. Switching to lightdm works around this (presumably it chooses video modes in a way that does not exactly match GNOME?), but not entirely reliably. smcv
