Re: 2 bugs in the X server

On Wed, 26 Jul 2006, Michal [utf-8] Maru?ka wrote:

> Hello,
> I know about 2 bugs in X server which are quite reproducible with my programs.
> I use CVS from a month ago, but I noticed the first bug months ago already.

> I use mga driver.

> 1/ There is a way to see a screen full of pixmaps (instead of what should be on
>   the screen).

>  I can reproduce this bug with sawfish WM.
>  It has a mode to flip between viewspaces, while moving a window by mouse
>  movement (and bumping into the border of the screen).

>  When I do such movement w/ keyboard using mouse emulation, I can trigger this funny
>  bug. Suddenly, after Sawfish does a series of requests to move windows, and
>  warp pointer, I see pictures which are used in my (running) firefox browser,
>  and I explain this that I see "off-screen" pixmaps.

>  To recover from the wrong display I can either switch to another  console, or
>  cycle resolution with  C-M-KP+/-.

I can't really help you with this problem, as I have no MGA hardware.

> 2/
>  DBE (double-buffer extension) operations can make the server segfault.

>  My guess is, that it is caused by the double-buffered window being too large:
>  the DBE request are made by my quick & dirty experimental code for Sawfish, to
>  draw window's title-bar, and the bug happens, when I construct a too large
>  window (building gtk view-text widget with a long line inside, w/o scrolling
>  enabled).

>  Here's the ....

> Caught signal 11.
> Stack trace:
> 0: 0x808da2c: 0x808da10 xf86ShowStackTrace + 0x1c
>        Module "XFree86"
> 1: 0x808db13: 0x808dab0 xf86SigHandler + 0x63
>        Module "XFree86"
> 2: 0xffffe420: 0xffffe420 __kernel_sigreturn + 0x0
>        Module ""
> 3: 0x813ca09: 0x813c8d0 miSpriteCopyArea + 0x139
>        Module "/usr/xfree86-4.6/bin/XFree86"
> 4: 0xb7f95420: 0xb7f95360 miDbeSwapBuffers + 0xc0
>        Module "/usr/xfree86-4.6/lib/modules/extensions/libdbe.a:midbe.o"
>        Section ".text"
> 5: 0xb7f967b4: 0xb7f96690 ProcDbeSwapBuffers + 0x124
>        Module "/usr/xfree86-4.6/lib/modules/extensions/libdbe.a:dbe.o"
>        Section ".text"
> 6: 0x80c5fba: 0x80c5e60 Dispatch + 0x15a
>        Module "XFree86"
> 7: 0x80d2327: 0x80d1f30 main + 0x3f7
>        Module "XFree86"

> Fatal server error:
> Server aborting

That displacement in miSpriteCopyArea doesn't match anything I have here, 
likely because I have different compiler versions.  Please do ...

 	gdb /usr/xfree86-4.6/bin/XFree86
 	disass miSpriteCopyArea
 	quit

... and send the resulting output.

> And I would like to ask, if there's a hope to get support for RV370[Radeon
> X300SE] in xfree86.

Well, such support would have to be contributed, as the author/maintainer of 
Radeon support has moved on to the X.Org Foundation.

> Thanks!

... and thank you!

Marc.

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