[Intel-gfx] 3.14.3 i915 dead display under X11

[Bruno Prémont]

CCing intel-gfx as otherwise it will probably not get seen by developers.

On Sun, 11 May 2014 Carbonated Beverage <ramune at psychosnugglebunnies.net> wrote:
> Hi all,
> 
> I rarely upgrade kernels these days -- so when updating to 3.14.3, I found
> the X display was blank -- switching to a text console appears to work, but
> I still have to type blind.
> 
> Symptoms:
> 
> Text mode and KMS works correctly to come up with the text console.  Running
> X (whether through xdm or /usr/bin/Xorg) causes the display to go blank
> and apparently turn off.  Switching to a text console via Control-Alt-F#
> leaves a mostly blank screen up, but there are brief flashes where it looks
> like the contents of the text console gets rendered once every 5 seconds or so,
> but so fast no words or letters can be recognized.
> 
> System:
> 
> * Thinkpad R61
> * 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 0c)
> * Debian/wheezy
> * xserver-xorg-video-intel 2:2.19.0-6
> 
> A diff of the Xorg.0.log (with timestamps removed, as it made almost every line
> show up in the diff) trimmed down shows:
> 
> @@ -53,7 +53,7 @@
>   (==) |-->Input Device "<default keyboard>"
>   (==) The core keyboard device wasn't specified explicitly in the layout.
>  	Using the default keyboard configuration.
> - (II) Loader magic: 0x7f2813451ae0
> + (II) Loader magic: 0x7f492c35aae0
>   (II) Module ABI versions:
>   	X.Org ANSI C Emulation: 0.4
>   	X.Org Video Driver: 12.1
> @@ -170,15 +170,17 @@
>  	Sandybridge Server, Ivybridge Mobile (GT1), Ivybridge Mobile (GT2),
>  	Ivybridge Desktop (GT1), Ivybridge Desktop (GT2), Ivybridge Server,
>  	Ivybridge Server (GT2)
> - (--) using VT number 7
> + (++) using VT number 7
>  
> + (WW) xf86OpenConsole: setpgid failed: Operation not permitted
> + (WW) xf86OpenConsole: setsid failed: Operation not permitted
>   (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
>   drmOpenDevice: node name is /dev/dri/card0
> - drmOpenDevice: open result is 10, (OK)
> + drmOpenDevice: open result is 8, (OK)
>   drmOpenByBusid: Searching for BusID pci:0000:00:02.0
>   drmOpenDevice: node name is /dev/dri/card0
> - drmOpenDevice: open result is 10, (OK)
> - drmOpenByBusid: drmOpenMinor returns 10
> + drmOpenDevice: open result is 8, (OK)
> + drmOpenByBusid: drmOpenMinor returns 8
>   drmOpenByBusid: drmGetBusid reports pci:0000:00:02.0
>   (**) intel(0): Depth 16, (--) framebuffer bpp 16
>   (==) intel(0): RGB weight 565
> @@ -387,7 +389,17 @@
>   (II) AutoAddDevices is off - not adding device.
>   (II) config/udev: Adding input device ThinkPad Extra Buttons (/dev/input/event5)
>   (II) AutoAddDevices is off - not adding device.
> - (II) AIGLX: Suspending AIGLX clients for VT switch
> - (II) UnloadModule: "kbd"
> - (II) UnloadModule: "mouse"
> - Server terminated successfully (0). Closing log file.
> + (II) intel(0): EDID vendor "LEN", prod id 16435
> + (II) intel(0): Printing DDC gathered Modelines:
> + (II) intel(0): Modeline "1440x900"x0.0   97.78  1440 1488 1520 1760  900 903 909 926 -hsync -vsync (55.6 kHz eP)
> + (II) intel(0): Modeline "1440x900"x0.0   81.49  1440 1488 1520 1760  900 903 909 926 -hsync -vsync (46.3 kHz e)
> + (II) intel(0): Modeline "800x600"x0.0   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz e)
> + (II) intel(0): Modeline "640x480"x0.0   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz e)
> + (II) intel(0): Modeline "1024x768"x0.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz e)
> + (II) intel(0): EDID vendor "LEN", prod id 16435
> + (II) intel(0): Printing DDC gathered Modelines:
> + (II) intel(0): Modeline "1440x900"x0.0   97.78  1440 1488 1520 1760  900 903 909 926 -hsync -vsync (55.6 kHz eP)
> + (II) intel(0): Modeline "1440x900"x0.0   81.49  1440 1488 1520 1760  900 903 909 926 -hsync -vsync (46.3 kHz e)
> + (II) intel(0): Modeline "800x600"x0.0   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz e)
> + (II) intel(0): Modeline "640x480"x0.0   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz e)
> + (II) intel(0): Modeline "1024x768"x0.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz e)
> 
> Bisecting from 3.13.6 (good) to 3.14.3 (bad) ended up with...
> 
> commit b35684b8fa94e04f55fd38bf672b737741d2f9e2
> Author: Jani Nikula <jani.nikula at intel.com>
> Date:   Thu Nov 14 12:13:41 2013 +0200
> 
>     drm/i915: do full backlight setup at enable time
>     
>     We should now have all the information we need to do a full
>     initialization of the backlight registers.
>     
>     v2: Keep QUIRK_NO_PCH_PWM_ENABLE for now (Imre).
>     
>     Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>     Reviewed-by: Imre Deak <imre.deak at intel.com>
>     Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> Which is in 3.12.0????
> 
> I'm not sure how that came to be.  Does that look right?  What other
> information would be required to track this down?
> 
> Thanks,
> 
> -- DN
> Daniel Nobuto