Xorg 7 I/O issues on sparc64

[Ludovic Courtès <ludo@chbouib.org>]

Hi,

I had reported some time ago problems running Xorg 7.0 on an Ultra 5 with
the ATI driver, including apparent file system corruption problems,
kernel crashes, etc. [0].  I tried out Xorg 7.1 with the 2.6.18-1 kernel
package recently and noticed that nothing had changed.  However, I
finally decided to remove that SunPCi board that sitted in my U5 (and was
useless anyway, due to the lack of free drivers) and noticed that doing
so made Xorg start and work flawlessly!

As I mentioned on the wiki, the kernel issues this kind of messages when
X starts (both with and without the SunPCi card):

  kernel: ioctl32(Xorg:2127): Unknown cmd fd(6) cmd(40584606){00} arg(ff5e1b0c) on /dev/fb0

Similarly, Xorg keeps issuing the following warning:

  (WW) ****INVALID IO ALLOCATION**** b: 0x2c00400 e: 0x2c004ff correcting^G

It seems that all this indicates that Xorg 7.x (or its ATI driver) is
doing something wrong wrt. I/O, or that it exercises an uncovered kernel
bug somehow.  Any idea of how we could dig this further, or to whom we
should report the problem?

Thanks,
Ludovic.

PS: I'll be away for one week and won't be able to reply until then.

[0] http://lists.debian.org/debian-sparc/2006/05/msg00008.html