Hm, it's a DP screen which I've suspected (those are the kind who can lose sync and go black). But somehow we don't get any hotplug event when this happens - so the driver has no idea that the link went bad and that we need to retrain. Can you please test this with this snippet: diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 1492706..5e91242 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2580,6 +2580,8 @@ intel_dp_hot_plug(struct intel_encoder *intel_encoder) { struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base); + printk("hotplug interrupt for DP\n"); + intel_dp_check_link_status(intel_dp); } Also please check whether yanking and re-plugging the DP cable will restore the display - it should. -Daniel On Sun, Jan 20, 2013 at 5:45 AM, Jonathan Adamczewski <jonathan.adamczewski at gmail.com> wrote: > Thanks for the reply, Daniel. > > Full traces are attached. I booted the system, ran dmesg after logging in > through kdm. > > (Then I left the system while doing some other errands, hence the gap in > time) > > I then started firefox, went to youtube and started watching some 4K > resolution videos. The external screen went black in less than a minute. > Second file is dmesg run after that - there doesn't appear to be much to > see... > > There was nothing in dmesg that correlated directly with the screen going > black. I've validated this by triggering the screen going black several > times (that's not in the attached log, though) - there was never anything in > dmesg that happened at the same time or that happened for tens of seconds > thereafter. > > > What's the next step for gathering information here? > > Many thanks > > Jonathan. > > > > > > On Sat, Jan 19, 2013 at 5:39 PM, Daniel Vetter <daniel at ffwll.ch> wrote: >> >> Hi Jonathan, >> >> Can you please boot with drm.debug=0xe and then attach the complete >> dmesg once right after boot, and once after the screen went black? >> >> Thanks, Daniel >> >> On Sun, Jan 20, 2013 at 1:38 AM, Jonathan Adamczewski >> <jonathan.adamczewski at gmail.com> wrote: >> > Hardware is a Dell XPS laptop, xorg log reports "Integrated Graphics >> > Chipset: Intel(R) Sandybridge Mobile (GT2)" >> > >> > Running a custom configured 3.7.2 based kernel, >> > xf86-video-intel-2.20.17. >> > >> > I'm running the internal LVDS screen at 1080p and a Dell 2713HM monitor >> > at >> > 2560x1440 connected via display port. >> > >> > Both screens run fine when X starts, but at some point the external >> > monitor >> > will go black. The system doesn't recognize it as being disconnected - >> > no >> > KDE popup asking if I want to change the monitor config as happens when >> > pulling the DP or power on the monitor. >> > >> > Sometimes it will return to life after a short amount of time, most of >> > the >> > time it stays black indefinitely. A full power cycle of the monitor >> > (pulling >> > the plug) will usually bring it back to life, but typically not for >> > long. >> > >> > The screen usually goes black while there's a high degree of display >> > activity - a video playing, moving large windows around the screen, >> > looking >> > around in google streetview, etc. It doesn't seem to matter which screen >> > the >> > activity is on. >> > >> > It *seems* to be less likely if I run the external display at a lower >> > resolution. >> > >> > There's nothing that coincides with the screen going black in dmesg or >> > the >> > xorg log. >> > >> > I've had no problems with this monitor under Windows 7 (gaming, videos, >> > etc). >> > >> > What I'm looking for: ideally a simple fix :) Otherwise, any suggestions >> > about where to look to gather more information on what could be >> > happening >> > here - or other places to ask for help. >> > >> > Many thanks >> > >> > jonathan. >> > >> > _______________________________________________ >> > Intel-gfx mailing list >> > Intel-gfx at lists.freedesktop.org >> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx >> > >> >> >> >> -- >> Daniel Vetter >> Software Engineer, Intel Corporation >> +41 (0) 79 365 57 48 - http://blog.ffwll.ch > > -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch