I have this problem with a freshly installed 10.04 Desktop. Sometimes it is as easy to reproduce as: Log in as user A, log in as user B, logout user B, black screen.(Xorg log below is of this scenario) It it not 100% reproducible and there are times I cannot reproduce it at all. It seems like when I cannot reproduce it any more I need to do a cold boot before the problem comes back.
VT switching via keyboard or chvt does not do anything. Stopping and starting gdm via initctl is the only way to bring the screen back short of rebooting
The following is sometimes logged by the kernel when switching or logging out users:
May 4 10:43:04 lws-template kernel: [ 150.586572] ------------[ cut here ]------------
May 4 10:43:04 lws-template kernel: [ 150.586600] WARNING: at /build/buildd/linux-2.6.32/lib/kref.c:43 kref_get+0x2d/0x30()
May 4 10:43:04 lws-template kernel: [ 150.586609] Hardware name: SFM27
May 4 10:43:04 lws-template kernel: [ 150.586614] Modules linked in: nfs lockd nfs_acl auth_rpcgss sunrpc autofs4 binfmt_misc ppdev fbcon tileblit font bitblit softcursor vga16fb vgastate joydev i915 drm_kms_helper drm i2c_algo_bit usbhid hid psmouse serio_raw video output intel_agp lp parport r8169 mii
May 4 10:43:04 lws-template kernel: [ 150.586696] Pid: 1014, comm: Xorg Not tainted 2.6.32-21-generic #32-Ubuntu
May 4 10:43:04 lws-template kernel: [ 150.586704] Call Trace:
May 4 10:43:04 lws-template kernel: [ 150.586722] [<ffffffff81066d0b>] warn_slowpath_common+0x7b/0xc0
May 4 10:43:04 lws-template kernel: [ 150.586736] [<ffffffff81066d64>] warn_slowpath_null+0x14/0x20
May 4 10:43:04 lws-template kernel: [ 150.586748] [<ffffffff812b468d>] kref_get+0x2d/0x30
May 4 10:43:04 lws-template kernel: [ 150.586784] [<ffffffffa0094a11>] drm_gem_handle_create+0x91/0xb0 [drm]
May 4 10:43:04 lws-template kernel: [ 150.586799] [<ffffffff8153f74e>] ? mutex_lock+0x1e/0x50
May 4 10:43:04 lws-template kernel: [ 150.586838] [<ffffffffa00fcd6b>] intel_user_framebuffer_create_handle+0x1b/0x20 [i915]
May 4 10:43:04 lws-template kernel: [ 150.586872] [<ffffffffa009f22e>] drm_mode_getfb+0x7e/0xc0 [drm]
May 4 10:43:04 lws-template kernel: [ 150.586900] [<ffffffffa0092e2a>] drm_ioctl+0x27a/0x480 [drm]
May 4 10:43:04 lws-template kernel: [ 150.586931] [<ffffffffa009f1b0>] ? drm_mode_getfb+0x0/0xc0 [drm]
May 4 10:43:04 lws-template kernel: [ 150.586946] [<ffffffff81282efd>] ? apparmor_file_alloc_security+0x2d/0xa0
May 4 10:43:04 lws-template kernel: [ 150.586961] [<ffffffff81085320>] ? autoremove_wake_function+0x0/0x40
May 4 10:43:04 lws-template kernel: [ 150.586976] [<ffffffff81152a92>] vfs_ioctl+0x22/0xa0
May 4 10:43:04 lws-template kernel: [ 150.586988] [<ffffffff81152d41>] do_vfs_ioctl+0x81/0x380
May 4 10:43:04 lws-template kernel: [ 150.587001] [<ffffffff81142a82>] ? vfs_write+0x132/0x1a0
May 4 10:43:04 lws-template kernel: [ 150.587015] [<ffffffff812506da>] ? security_capable+0x2a/0x30
May 4 10:43:04 lws-template kernel: [ 150.587027] [<ffffffff81071a83>] ? capable+0x13/0x50
May 4 10:43:04 lws-template kernel: [ 150.587039] [<ffffffff811530c1>] sys_ioctl+0x81/0xa0
May 4 10:43:04 lws-template kernel: [ 150.587054] [<ffffffff810131b2>] system_call_fastpath+0x16/0x1b
May 4 10:43:04 lws-template kernel: [ 150.587064] ---[ end trace 18873645e6cf4e0f ]---
Note that there are times that the above is logged but the screen does not blank out and Xorg continues to function.
/var/log/Xorg.0.log attached. This log is up to the point where the screen blanks.
I have this problem with a freshly installed 10.04 Desktop. Sometimes it is as easy to reproduce as: Log in as user A, log in as user B, logout user B, black screen.(Xorg log below is of this scenario) It it not 100% reproducible and there are times I cannot reproduce it at all. It seems like when I cannot reproduce it any more I need to do a cold boot before the problem comes back.
VT switching via keyboard or chvt does not do anything. Stopping and starting gdm via initctl is the only way to bring the screen back short of rebooting
The following is sometimes logged by the kernel when switching or logging out users:
May 4 10:43:04 lws-template kernel: [ 150.586572] ------------[ cut here ]------------ buildd/ linux-2. 6.32/lib/ kref.c: 43 kref_get+ 0x2d/0x30( ) d0b>] warn_slowpath_ common+ 0x7b/0xc0 d64>] warn_slowpath_ null+0x14/ 0x20 68d>] kref_get+0x2d/0x30 a11>] drm_gem_ handle_ create+ 0x91/0xb0 [drm] 74e>] ? mutex_lock+ 0x1e/0x50 d6b>] intel_user_ framebuffer_ create_ handle+ 0x1b/0x20 [i915] 22e>] drm_mode_ getfb+0x7e/ 0xc0 [drm] e2a>] drm_ioctl+ 0x27a/0x480 [drm] 1b0>] ? drm_mode_ getfb+0x0/ 0xc0 [drm] efd>] ? apparmor_ file_alloc_ security+ 0x2d/0xa0 320>] ? autoremove_ wake_function+ 0x0/0x40 a92>] vfs_ioctl+0x22/0xa0 d41>] do_vfs_ ioctl+0x81/ 0x380 a82>] ? vfs_write+ 0x132/0x1a0 6da>] ? security_ capable+ 0x2a/0x30 a83>] ? capable+0x13/0x50 0c1>] sys_ioctl+0x81/0xa0 1b2>] system_ call_fastpath+ 0x16/0x1b
May 4 10:43:04 lws-template kernel: [ 150.586600] WARNING: at /build/
May 4 10:43:04 lws-template kernel: [ 150.586609] Hardware name: SFM27
May 4 10:43:04 lws-template kernel: [ 150.586614] Modules linked in: nfs lockd nfs_acl auth_rpcgss sunrpc autofs4 binfmt_misc ppdev fbcon tileblit font bitblit softcursor vga16fb vgastate joydev i915 drm_kms_helper drm i2c_algo_bit usbhid hid psmouse serio_raw video output intel_agp lp parport r8169 mii
May 4 10:43:04 lws-template kernel: [ 150.586696] Pid: 1014, comm: Xorg Not tainted 2.6.32-21-generic #32-Ubuntu
May 4 10:43:04 lws-template kernel: [ 150.586704] Call Trace:
May 4 10:43:04 lws-template kernel: [ 150.586722] [<ffffffff81066
May 4 10:43:04 lws-template kernel: [ 150.586736] [<ffffffff81066
May 4 10:43:04 lws-template kernel: [ 150.586748] [<ffffffff812b4
May 4 10:43:04 lws-template kernel: [ 150.586784] [<ffffffffa0094
May 4 10:43:04 lws-template kernel: [ 150.586799] [<ffffffff8153f
May 4 10:43:04 lws-template kernel: [ 150.586838] [<ffffffffa00fc
May 4 10:43:04 lws-template kernel: [ 150.586872] [<ffffffffa009f
May 4 10:43:04 lws-template kernel: [ 150.586900] [<ffffffffa0092
May 4 10:43:04 lws-template kernel: [ 150.586931] [<ffffffffa009f
May 4 10:43:04 lws-template kernel: [ 150.586946] [<ffffffff81282
May 4 10:43:04 lws-template kernel: [ 150.586961] [<ffffffff81085
May 4 10:43:04 lws-template kernel: [ 150.586976] [<ffffffff81152
May 4 10:43:04 lws-template kernel: [ 150.586988] [<ffffffff81152
May 4 10:43:04 lws-template kernel: [ 150.587001] [<ffffffff81142
May 4 10:43:04 lws-template kernel: [ 150.587015] [<ffffffff81250
May 4 10:43:04 lws-template kernel: [ 150.587027] [<ffffffff81071
May 4 10:43:04 lws-template kernel: [ 150.587039] [<ffffffff81153
May 4 10:43:04 lws-template kernel: [ 150.587054] [<ffffffff81013
May 4 10:43:04 lws-template kernel: [ 150.587064] ---[ end trace 18873645e6cf4e0f ]---
Note that there are times that the above is logged but the screen does not blank out and Xorg continues to function.
/var/log/Xorg.0.log attached. This log is up to the point where the screen blanks.
No /etc/X11/xorg.conf.
$ lspci -s 00:02.0 -nn -v
00:02.0 VGA compatible controller [0300]: Intel Corporation 82945G/GZ Integrated Graphics Controller [8086:2772] (rev 02)
Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Device [1297:3166]
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at fdf00000 (32-bit, non-prefetchable) [size=512K]
I/O ports at ff00 [size=8]
Memory at d0000000 (32-bit, prefetchable) [size=256M]
Memory at fdf80000 (32-bit, non-prefetchable) [size=256K]
Capabilities: <access denied>
Kernel driver in use: i915
Kernel modules: i915