Bug#374839: xserver-xorg-core: rapid scrolling or repainting scrambles xterm or emacs display
Package: xserver-xorg-core
Version: 1:1.0.2-8
Severity: normal
After a recent apt-get upgrade, I have noticed severe problems with
the screen becoming garbled on my Thinkpad X40. This may happen only
after an APM resume; I'm not sure. Strangely, the problem can
sometimes be cured by repeatedly switching back and forth between
internal and external display using Fn-F7.
I'm not sure how to describe the symptoms; the best I can do is that a
thin strip of scan lines---maybe three pixels high or so---becomes
replicated across a large fraction of the window, and the rest of the
window goes blank. It's almost as if the scan lines are scrambled
somehow. The effect is confined to a single window and doesn't affect
other windows on the same screen.
The two applications where the problem shows up consistently are xterm
and emacs:
* When xterm scrolls, the part of the window that is newly painted
becomes scrambles. The problem can be mitigated by setting 'Jump
Scrolling' off in the xterm's ctrl-middle-click window.
* When emacs scrolls and repaints, the window can become scrambled,
and typing ctrl-l to refresh the window scrambles the window
completely.
Most interestingly, if I use my window manager to change virtual
panels on the desktop (I'm using fvwm), switching away from and back
to the offending application completely cures the screen. Likewise,
forcing a scrambled window to the bottom and then to the top fixes the
problem. Finally, dragging a small window over a bad window causes
the obscured regions to be repaired when they are uncovered again.
All these symptoms lead me to conjecture that when the app is asked to
paint the screen, it works fine, but some kinds of scrolling requests
cause the strangeness. That's why I'm reporting the bug against
/usr/bin/Xorg (my best guess) as opposed to something else.
I know this one is going to be hard to reproduce; please let me know
if I can provide other information. (And I'm not sure I know how to
downgrade to a previous version, but if you would like me to try that
and check for results, let me know that too.)
-- System Information:
Debian Release: testing/unstable
APT prefers testing
APT policy: (500, 'testing'), (500, 'stable'), (50, 'unstable')
Architecture: i386 (i686)
Shell: /bin/sh linked to /bin/bash
Kernel: Linux 2.6.15-1-686
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Versions of packages xserver-xorg-core depends on:
ii libc6 2.3.6-13 GNU C Library: Shared libraries
ii libfontenc1 1:1.0.1-6 X11 font encoding library
ii libgcc1 1:4.1.0-4 GCC support library
ii libxau6 1:1.0.0-3 X11 authorisation library
ii libxdmcp6 1:1.0.0-4 X11 Display Manager Control Protoc
ii libxfont1 1:1.0.0-4 X11 font rasterisation library
ii x11-common 1:7.0.22 X Window System (X.Org) infrastruc
ii xserver-xorg-input-al 1:7.0.22 the X.Org X server -- input driver
ii xserver-xorg-input-ev 1:1.0.0.5-2 X.Org X server -- evdev input driv
ii xserver-xorg-input-kb 1:1.0.1.3-2 X.Org X server -- keyboard input d
ii xserver-xorg-input-mo 1:1.0.4-3 X.Org X server -- mouse input driv
ii xserver-xorg-video-al 1:7.0.22 the X.Org X server -- output drive
ii xserver-xorg-video-ap 1:1.0.1.5-2 X.Org X server -- APM display driv
ii xserver-xorg-video-ar 1:0.5.0.5-2 X.Org X server -- ark display driv
ii xserver-xorg-video-at 1:6.5.8.0-1 X.Org X server -- ATI display driv
ii xserver-xorg-video-ch 1:1.0.1.3-3 X.Org X server -- Chips display dr
ii xserver-xorg-video-ci 1:1.0.0.5-2 X.Org X server -- Cirrus display d
ii xserver-xorg-video-cy 1:1.0.0.5-2 X.Org X server -- Cyrix display dr
ii xserver-xorg-video-du 1:0.1.0.5-2 X.Org X server -- dummy display dr
ii xserver-xorg-video-fb 1:0.1.0.5-2 X.Org X server -- fbdev display dr
ii xserver-xorg-video-gl 1:1.0.1.3-3 X.Org X server -- Glint display dr
ii xserver-xorg-video-i1 1:1.1.0.5-2 X.Org X server -- i128 display dri
ii xserver-xorg-video-i7 1:1.0.0.5-2 X.Org X server -- i740 display dri
ii xserver-xorg-video-i8 1:1.5.1.0-2 X.Org X server -- Intel i8xx, i9xx
ii xserver-xorg-video-im 1:1.0.0.5-2 X.Org X server -- IMSTT display dr
ii xserver-xorg-video-mg 1:1.2.1.3.dfsg.1-2 X.Org X server -- MGA display driv
ii xserver-xorg-video-ne 1:1.0.0.5-2 X.Org X server -- Neomagic display
ii xserver-xorg-video-ne 1:0.1.4.1-3 X.Org X server -- Newport display
ii xserver-xorg-video-ns 1:2.7.6.5-2 X.Org X server -- NSC display driv
ii xserver-xorg-video-nv 1:1.0.1.5-2 X.Org X server -- NV display drive
ii xserver-xorg-video-re 1:4.0.1.3.dfsg.1-2 X.Org X server -- Rendition displa
ii xserver-xorg-video-s3 1:1.8.6.5-2 X.Org X server -- S3 ViRGE display
ii xserver-xorg-video-sa 1:2.0.2.3-4 X.Org X server -- Savage display d
ii xserver-xorg-video-si 1:1.3.1.5-3 X.Org X server -- SiliconMotion di
ii xserver-xorg-video-si 1:0.8.1.3-2 X.Org X server -- SiS display driv
ii xserver-xorg-video-si 1:0.7.1.3-2 X.Org X server -- SiS USB display
ii xserver-xorg-video-td 1:1.1.1.3-3 X.Org X server -- tdfx display dri
ii xserver-xorg-video-tg 1:1.0.0.5-3 X.Org X server -- TGA display driv
ii xserver-xorg-video-tr 1:1.0.1.2-2 X.Org X server -- Trident display
ii xserver-xorg-video-ts 1:1.0.0.5-2 X.Org X server -- Tseng display dr
ii xserver-xorg-video-v4 0.0.1.5-1 X.Org X server -- Video 4 Linux di
ii xserver-xorg-video-ve 1:1.0.1.3-2 X.Org X server -- VESA display dri
ii xserver-xorg-video-vg 1:4.0.0.5-2 X.Org X server -- VGA display driv
ii xserver-xorg-video-vi 1:0.1.33.2-3 X.Org X server -- VIA display driv
ii xserver-xorg-video-vm 1:10.11.1.3-2 X.Org X server -- VMware display d
ii xserver-xorg-video-vo 1:1.0.0.5-2 X.Org X server -- Voodoo display d
ii zlib1g 1:1.2.3-11 compression library - runtime
Versions of packages xserver-xorg-core recommends:
pn xkeyboard-config <none> (no description available)
-- no debconf information
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