Hi, I've noticed recently (probably in the upgrade from Kubuntu 12.10 to Kubuntu 13.04), that the screen occasionally glitches out, perhaps once every few days. The screen freezes for a few seconds, and then resumes. When it resumes, it refreshes extremely slowly. For example, alt-tabbing through Firefox windows looks terrible. Each new window takes a half seconds to appear, and I can see the screen drawing the window from the top down. It looks like it is drawing every alternate line first, flowing from the top, then every remaining line next. If I'm playing a game, I get about 1–2 frames per second. I'm not sure if it's graphics driver related, because I'm using a (dual) optimus Nvidia card with bumblebee. I see this problem in games (i.e. on the Nvidia card) or in Firefox (i.e. on the integrated Intel chip, even when the Nvidia is inactive).
I've tried replacing plasma with `kbuildsycoca4 ; kquitapp plasma-desktop ; sleep 2 ; kstart plasma-desktop`, but this does not fix it. The only real fix is restarting or logging out and back in. If I remain logged in (with it broken) then log into another account simultaneously, the graphics are fine.
Temporarily disabling compositing does make the graphics more responsive. It's certainly usable, but feels slightly less responsive to what I'm used to. However, I think this does not solve it. I tried watching a full-HD 50-FPS video in VLC, and it failed. Audio played fine, but the video was stuck on the first frame. I tried with both OpenGL and XRender, with compositing turned both on and off (i.e. four permutations). (Again, XRender was responsive enough for low-performance usage, but not good enough to play high-quality videos.)
In /var/log/kern.log, I found:
There was nothing at /debug/dri/0/i915_error_state, but there was a file at /sys/kernel/debug/dri/0/i915_error_state . I've somehow lost it, but I'll upload it next time I see the error.
I'm using a Dell XPS 17 L702X. The CPU is Sandy Bridge (Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz).
(FWIW, I was recommended to post in this forum after initially asking at forum.kde.org.)
I've tried replacing plasma with `kbuildsycoca4 ; kquitapp plasma-desktop ; sleep 2 ; kstart plasma-desktop`, but this does not fix it. The only real fix is restarting or logging out and back in. If I remain logged in (with it broken) then log into another account simultaneously, the graphics are fine.
Temporarily disabling compositing does make the graphics more responsive. It's certainly usable, but feels slightly less responsive to what I'm used to. However, I think this does not solve it. I tried watching a full-HD 50-FPS video in VLC, and it failed. Audio played fine, but the video was stuck on the first frame. I tried with both OpenGL and XRender, with compositing turned both on and off (i.e. four permutations). (Again, XRender was responsive enough for low-performance usage, but not good enough to play high-quality videos.)
In /var/log/kern.log, I found:
Code:
May 25 13:32:29 sparhawk-XPS-17 kernel: [13549.869879] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung May 25 13:32:29 sparhawk-XPS-17 kernel: [13549.869885] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state
I'm using a Dell XPS 17 L702X. The CPU is Sandy Bridge (Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz).
Code:
$ lspci -k|grep -i -A2 vga 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) Subsystem: Dell Device 0571 Kernel driver in use: i915 -- 01:00.0 VGA compatible controller: NVIDIA Corporation GF116M [GeForce GT 555M/635M] (rev ff) 03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6230 [Rainbow Peak] (rev 34) Subsystem: Intel Corporation Centrino Advanced-N 6230 AGN
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