i810 crashes when switching bewteen X and text console

[loic.mahe@xxxxxxxxxxxxxx]

Hello,

I've found a problem with XFree 4.6
on the Dell Optiplex GX110, which has
an Intel i810E graphics chipset (i810
module). It worked well in XFree86 4.5.

X startx normally, but when switching
back to text console and again to X server,
the screen becomes dark and the text
consoles become unusable too.
The system doesn't crash and I can see
this in /var/log/XFree86.0.log

Fatal server error:
EnterVT failed for screen 0


When reporting a problem related to
a server crash, please send
the full server output, not just the
last messages.
This can be found in the log file "/var/log/XFree86.0.log".

Error in I810WaitLpRing(), now is 61278,
start is 59277
pgetbl_ctl: 0x1bc0001 pgetbl_err: 0x0
ipeir: 0 iphdr: 0
LP ring tail: 8 head: 0 len: 0 start
0
eir: 0 esr: 0 emr: 3d
instdone: ff7b instpm: 0
memmode: 4 instps: 0
hwstam: 9ac7 ier: 0 imr: 9ac7 iir: 0
space: 65520 wanted 65528
(II) I810(0): [drm] removed 1 reserved
context for kernel
(II) I810(0): [drm] unmapping 8192 bytes
of SAREA 0xc89e2000 at 0x4061c000

FatalError re-entered, aborting
lockup


The following lines can be found in
the dmesg :

[drm] Using v1.4 init.
[drm:i810_wait_ring] *ERROR* space:
65512 wanted 65528
[drm:i810_wait_ring] *ERROR* lockup
[drm:i810_wait_ring] *ERROR* space:
65504 wanted 65528
[drm:i810_wait_ring] *ERROR* lockup
mtrr: base(0xf8000000) is not aligned
on a size(0x180000) boundary


The only solution I found to avoid it
was this option for the i810 device :

Option "DRI" "no"

I noted this problem with XFree 4.6.0
+ patches 1-7.

Loïc, Toulouse, France