nouveau nvidia crashing

[Seb <spluque@gmail.com>]

Hi,

I'm not sure I'm troubleshooting this correctly, but here is what I know
so far.  An AMD64 Debian sid system with an Nvidia card, which it uses
with the xserver-xorg-video-nouveau package.  The system randomly (I
can't identify exactly what is triggering it because it happens under
many circumstances, including not running anything on the desktop)
freezes; the desktop screen doesn't change, cursor may or may not be
possible, but the system is otherwise completely unresponsive.  I have
to manually shut down the computer and restart to get control back.
However, I'm able to SSH into the computer from elsewhere, and that's
how I've gathered the relevant logs (output of dmesg -dk, and
/var/log/Xorg.0.log).  I'm attaching the output of dmesg to this
message.  I think these are the relevant lines at the bottom occur when
the system hangs:

[ 3866.093926 < 3811.456518>] [drm] nouveau 0000:00:0d.0: fail pre-validate sync
[ 3866.093938 <    0.000012>] [drm] nouveau 0000:00:0d.0: validate vram_list
[ 3866.093950 <    0.000012>] [drm] nouveau 0000:00:0d.0: validate: -16

and in Xorg.0.log:

[  3871.516] [mi] EQ overflowing. The server is probably stuck in an infinite loop.
[  3871.517] 
Backtrace:
[  3871.623] 0: /usr/bin/X (xorg_backtrace+0x26) [0x7f9b65f15476]
[  3871.623] 1: /usr/bin/X (mieqEnqueue+0x191) [0x7f9b65ef5d81]
[  3871.623] 2: /usr/bin/X (0x7f9b65d91000+0x65214) [0x7f9b65df6214]
[  3871.623] 3: /usr/bin/X (xf86PostButtonEvent+0xdd) [0x7f9b65e30d9d]
[  3871.623] 4: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9b5ef15000+0x4aa3) [0x7f9b5ef19aa3]
[  3871.623] 5: /usr/bin/X (0x7f9b65d91000+0x8a907) [0x7f9b65e1b907]
[  3871.623] 6: /usr/bin/X (0x7f9b65d91000+0xb04ee) [0x7f9b65e414ee]
[  3871.623] 7: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f9b650b9000+0xf030) [0x7f9b650c8030]
[  3871.623] 8: /lib/x86_64-linux-gnu/libc.so.6 (ioctl+0x7) [0x7f9b63e94957]
[  3871.623] 9: /usr/lib/x86_64-linux-gnu/libdrm.so.2 (drmIoctl+0x28) [0x7f9b62213a28]
[  3871.623] 10: /usr/lib/x86_64-linux-gnu/libdrm.so.2 (drmCommandWrite+0x1b) [0x7f9b62215d1b]
[  3871.624] 11: /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1 (0x7f9b61bc4000+0x3197) [0x7f9b61bc7197]
[  3871.624] 12: /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1 (nouveau_bo_map_range+0x109) [0x7f9b61bc77b9]
[  3871.624] 13: /usr/lib/xorg/modules/drivers/nouveau_drv.so (0x7f9b61dca000+0x74eb) [0x7f9b61dd14eb]
[  3871.624] 14: /usr/lib/xorg/modules/libexa.so (0x7f9b61179000+0xb586) [0x7f9b61184586]
[  3871.624] 15: /usr/bin/X (0x7f9b65d91000+0x174431) [0x7f9b65f05431]
[  3871.624] 16: /usr/bin/X (0x7f9b65d91000+0xd63e3) [0x7f9b65e673e3]
[  3871.624] 17: /usr/lib/xorg/modules/libexa.so (exaGetPixmapFirstPixel+0x71) [0x7f9b6118c1c1]
[  3871.624] 18: /usr/lib/xorg/modules/libexa.so (0x7f9b61179000+0xf814) [0x7f9b61188814]
[  3871.624] 19: /usr/bin/X (0x7f9b65d91000+0x114ed4) [0x7f9b65ea5ed4]
[  3871.624] 20: /usr/bin/X (0x7f9b65d91000+0x10d474) [0x7f9b65e9e474]
[  3871.624] 21: /usr/bin/X (0x7f9b65d91000+0x51f81) [0x7f9b65de2f81]
[  3871.624] 22: /usr/bin/X (0x7f9b65d91000+0x411aa) [0x7f9b65dd21aa]
[  3871.624] 23: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xfd) [0x7f9b63de1ead]
[  3871.624] 24: /usr/bin/X (0x7f9b65d91000+0x4149d) [0x7f9b65dd249d]

Any tips on how to narrow this down appreciated.

Cheers,

-- 
Seb