Bug 21217 - [945GM KMS] Blank black screen on xserver startup with UXA. (Dell Latitude D820)
Summary: [945GM KMS] Blank black screen on xserver startup with UXA. (Dell Latitude D820)
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: unspecified
Hardware: x86-64 (AMD64) Linux (All)
: medium critical
Assignee: Jesse Barnes
QA Contact:
URL:
Whiteboard:
Keywords: NEEDINFO
Depends on:
Blocks:
 
Reported: 2009-04-16 03:41 UTC by aszlig
Modified: 2017-07-24 23:10 UTC (History)
3 users (show)

See Also:
i915 platform:
i915 features:


Attachments
dmesg (30.23 KB, text/plain)
2009-04-16 03:41 UTC, aszlig
no flags Details
xorg logfile (17.88 KB, text/plain)
2009-04-16 03:41 UTC, aszlig
no flags Details
register dump before xserver start (7.75 KB, text/plain)
2009-04-20 09:38 UTC, aszlig
no flags Details
register dump after xserver start (7.77 KB, text/plain)
2009-04-20 09:38 UTC, aszlig
no flags Details
GPU dump after xserver start (101.53 KB, application/x-gzip)
2009-04-21 11:34 UTC, aszlig
no flags Details

Description aszlig 2009-04-16 03:41:01 UTC
Created attachment 24847 [details]
dmesg

distribution: debian gnu/linux sid/experimental with amd64

kernel version: 2.6.30-rc2
architecture: x86_64

on a Dell Latitude D820 using LVDS (no other screens attached).

xf86-video-intel: git commit 2e3b95ed0197971e81ab7509245c899e96859d5b
xserver: 1.6.1 (debian sid/experimental)
mesa: 7.4-2 (debian sid/experimental)
libdrm: 2.4.9+git20090414.07646002-1ubuntu3sarvatt

Easy to reproduce here by just trying to start the xserver with UXA enabled. I
get a black screen and i'm unable to change back to a VT anymore. Just got the
log by syncing/killing/rebooting using sysrq. sysrq+g doesn't work either.

"buscher" in IRC seems to have the same problem on the MacBook 2, with the
difference that it works with EXA there. Unfortunately I get the same result
with UXA. For me it doesn't make any difference if using with and/or without
PAT and Tiling leading always to that black screen.

here is the xorg.conf:

Section "Device"
        Identifier      "Configured Video Device"
        Option          "AccelMethod"   "UXA"
        Option          "ModeDebug"     "yes"
EndSection

dmesg and Xorg.0.log are attached.
Comment 1 aszlig 2009-04-16 03:41:51 UTC
Created attachment 24848 [details]
xorg logfile
Comment 2 aszlig 2009-04-20 09:38:01 UTC
Created attachment 24971 [details]
register dump before xserver start
Comment 3 aszlig 2009-04-20 09:38:32 UTC
Created attachment 24972 [details]
register dump after xserver start
Comment 4 aszlig 2009-04-21 11:34:55 UTC
Created attachment 25005 [details]
GPU dump after xserver start
Comment 5 aszlig 2009-05-04 11:18:05 UTC
it works when the drm stuff isn't built-in into the kernel and modprobed later.

my first guess was that it may have problems with the agpart module which may
be loaded afther drm, but i checked and that wasn't the case.
Comment 6 Jesse Barnes 2009-05-11 11:56:21 UTC
I think we went over this on IRC but now I've forgotten. :/

I think the builtin vs. modprobed issue should be gone now, and if not we should fix it, but I'm not sure that's behind this problem.

We recently found that some distros run vbetool at bootup, which was causing interrupts to get disabled, preventing any rendering from completing.  So that could be one cause of this bug.

If that's not it, can you get a backtrace of X when it displays the blank screen?  It's probably stuck trying to render into the front buffer, but I'd like to get that confirmed.  Also, please copy out the contents of the debugfs files and attach them here during the failure.
  # mount -t debugfs nodev /sys/kernel/debug
  # cd /sys/kernel/debug/dri/0
  # mkdir /tmp/gpu-debug; cp * /tmp/gpu-debug
Comment 7 Julien Muchembled 2009-05-11 14:52:28 UTC
I added myself to the CC list because I had the same issue (read: same symptoms), with a "Mobile Intel GMA 4500MHD" (8086:2a43). Linux 2.6.29.1 (vanilla) & driver 2.6.1 (from Debian)
I had all graphics stuff as modules so I don't think it matters.

KMS works since I upgraded to 2.6.29.3 + 2.7.0. Now, I even have i915 buitin.
Comment 8 aszlig 2009-05-13 09:20:39 UTC
Works for me now (tested with 2.6.30-rc5) and thus closed :-)


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