On Tuesday, January 13, 2009 6:58 am Peter Clifton wrote: > On Tue, 2009-01-13 at 17:26 +0800, Jin, Gordon wrote: > > Peter Clifton wrote on Tuesday, January 13, 2009 11:45 AM: > > > On Tue, 2009-01-13 at 01:55 +0000, Peter Clifton wrote: > > >> Testing git HEAD intel drivers, also recent Xorg: > > >> > > >> > > >> After the problem with miss-detected TV-out, I killed Xorg with a > > >> Ctrl +Alt+Backspace (I've got zapping re-enabled in my xorg.conf), > > >> and the outputs detected properly, with no TV output detected as > > >> being connected. > > >> > > >> The performance was very slow, however, and with the characteristic > > >> "jiggle" / jittering of the mouse cursor position which I've > > > > noticed > > > > >> on both my Intel based machines during output detection. > > >> > > >> Trying xrandr, adjusting brightness, had no effect. A couple of VT > > >> switches to VT1 and back to Xorg finally stopped the detection > > > > loop, > > > > >> although during that process, one of the the switches to VT1 left > > > > me > > > > >> with a corrupted console. (Possibly scanning out from the wrong > > > > part > > > > >> of the frame-buffer, perhaps with the wrong sync settings?). > > >> > > >> I've attached the log. It does show a page-table problem with the > > >> last VT switch. > > > > > > I managed to re-trigger this bug by pulling the laptop's AC power > > > adaptor out, and plugging it back in again. I suspect either an ACPI > > > event, or something inside HP's SMM BIOS code triggered it. My old > > > > HP > > > > > nc 6320 didn't properly respect _DOS bit 4, so would always fiddle > > > with the graphics hardware when you plugged / unplugged the AC > > > adaptor. > > > > > > I've not dug deeply into this one, so I'm not quite blaming the BIOS > > > yet, however it is looking somewhat guilty. > > > > This looks similar to > > http://bugs.freedesktop.org/show_bug.cgi?id=19431, interesting bug. > > It only bears very supercficial similarities as far as I can see. > > Yes, I had a problem with intermittent TV out detection, but that > doesn't appear to be dependent on battery state. > > My problem is that "something" (often triggered by an AC state change, > but sometimes just when I boot up) is triggering a storm of probes to > detect outputs. I did wonder if this might be due to a faulty detection > routine trying to spot that I inserted a cable in one of the outputs, > however this backtrace I grabbed whilst the problem was occuring > suggests that it is being dispatched through the X server: > > #0 0xb809e430 in __kernel_vsyscall () > #1 0xb7ce7700 in __nanosleep_nocancel () from /lib/tls/i686/cmov/libc.so.6 > #2 0xb7d24ffc in usleep () from /lib/tls/i686/cmov/libc.so.6 > #3 0xb7ab826e in i830WaitForVblank (pScreen=0xa197040) at > ../../src/i830_display.c:379 #4 0xb7abaf80 in i830_crtc_mode_set > (crtc=0xa199b80, mode=0xbfdb9ea0, adjusted_mode=0xa4d70e8, x=0, y=0) at > ../../src/i830_display.c:1511 #5 0x080ed08d in xf86CrtcSetModeTransform > (crtc=0xa199b80, mode=0xbfdb9ea0, rotation=1, transform=0x0, x=0, y=0) at > ../../../../hw/xfree86/modes/xf86Crtc.c:366 > #6 0x080ed6d6 in xf86CrtcSetMode (crtc=0xa199b80, mode=0xbfdb9ea0, > rotation=8180, x=0, y=0) at ../../../../hw/xfree86/modes/xf86Crtc.c:413 #7 > 0xb7ab956d in i830GetLoadDetectPipe (output=0xa19b618, mode=0xbfdb9ea0, > dpms_mode=0xbfdb9f78) at ../../src/i830_display.c:1811 #8 0xb7ad746d in > i830_tv_detect (output=0xa19b618) at ../../src/i830_tv.c:1376 #9 > 0x080eda90 in xf86ProbeOutputModes (scrn=0xa197040, maxX=4096, maxY=4096) > at ../../../../hw/xfree86/modes/xf86Crtc.c:1500 #10 0x080f56c0 in > xf86RandR12GetInfo12 (pScreen=0xa19c460, rotations=0xbfdba16a) at > ../../../../hw/xfree86/modes/xf86RandR12.c:1255 #11 0x08162e89 in RRGetInfo > (pScreen=0xa19c460) at ../../randr/rrinfo.c:196 #12 0x08167084 in > ProcRRGetScreenSizeRange (client=0xa3d2208) at ../../randr/rrscreen.c:227 > #13 0x0815f305 in ProcRRDispatch (client=0x0) at ../../randr/randr.c:473 > #14 0x0808cdbf in Dispatch () at ../../dix/dispatch.c:437 > #15 0x08071aad in main (argc=10, argv=0xbfdba324, envp=Cannot access memory > at address 0x8 ) at ../../dix/main.c:383 > > > Does anyone know if there is an easy way to ascertain from a backtrace, > which client caused a particular dispatch? (Perhaps chasing back > through /proc/ or netstat to find out more info on the actual process > involved?
Well, the randr functions are in the backtrace, so it's possible some application is triggering the re-probe. That doesn't mean your BIOS isn't causing trouble though: it could be sending ACPI events that are getting picked up by some app which is then doing a re-probe. You should be able to check out your ACPI daemon log or use acpi_listen to see if that's happening. -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ xorg mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/xorg
