X freezes completely and I am also unable to restart it (using SSH) or switch to a virtual console. It seems to me like the whole graphics card hung up. I have tried different kernel versions (4.3.0, 4.1.13, 3.18.24) as well as the free nouveau driver (1.0.11) and the proprietary Nvidia driver (1:352.55). The freezes are totally unpredictable, sometimes it works for hours and sometimes they happen direct after X has started. I am using Manjaro Linux with Xorg 1.17.4.

Xorg Log:
(EE) [mi] EQ overflowing.  Additional events will be discarded until existing events are processed.
(EE) 
(EE) Backtrace:
(EE) 0: /usr/lib/xorg-server/Xorg (mieqEnqueue+0x253) [0x5743e3]
(EE) 1: /usr/lib/xorg-server/Xorg (QueuePointerEvents+0x52) [0x450f02]
(EE) 2: /usr/lib/xorg/modules/input/evdev_drv.so (_init+0x3103) [0x7fe70ab02ee3]
(EE) 3: /usr/lib/xorg/modules/input/evdev_drv.so (_init+0x396d) [0x7fe70ab0431d]
(EE) 4: /usr/lib/xorg-server/Xorg (DPMSSupported+0xe8) [0x477a88]
(EE) 5: /usr/lib/xorg-server/Xorg (xf86SerialModemClearBits+0x2b2) [0x4a13f2]
(EE) 6: /usr/lib/libc.so.6 (__restore_rt+0x0) [0x7fe715bbc67f]
(EE) 7: /usr/lib/libc.so.6 (ioctl+0x5) [0x7fe715c6a795]
(EE) 8: /usr/lib/libdrm.so.2 (drmIoctl+0x28) [0x7fe716d24388]
(EE) 9: /usr/lib/libdrm.so.2 (drmCommandWrite+0x1b) [0x7fe716d2704b]
(EE) 10: /usr/lib/libdrm_nouveau.so.2 (nouveau_bo_wait+0x8c) [0x7fe7104728fc]
(EE) 11: /usr/lib/libdrm_nouveau.so.2 (nouveau_pushbuf_space+0xd6) [0x7fe710473c86]
(EE) 12: /usr/lib/xorg/modules/drivers/nouveau_drv.so (_init+0x1fb89) [0x7fe7106bbac9]
(EE) 13: /usr/lib/xorg/modules/libexa.so (exaEnableDisableFBAccess+0xecc) [0x7fe70fe3fb4c]
(EE) 14: /usr/lib/xorg/modules/libexa.so (exaEnableDisableFBAccess+0x19d1) [0x7fe70fe41131]
(EE) 15: /usr/lib/xorg-server/Xorg (DamageRegionAppend+0x621) [0x51b391]
(EE) 16: /usr/lib/xorg-server/Xorg (AddTraps+0x40e7) [0x5149f7]
(EE) 17: /usr/lib/xorg-server/Xorg (SendErrorToClient+0x2ff) [0x438fbf]
(EE) 18: /usr/lib/xorg-server/Xorg (remove_fs_handlers+0x41b) [0x43d09b]
(EE) 19: /usr/lib/libc.so.6 (__libc_start_main+0xf0) [0x7fe715ba9610]
(EE) 20: /usr/lib/xorg-server/Xorg (_start+0x29) [0x427489]
(EE) 21: ? (?+0x29) [0x29]
(EE) 
(EE) [mi] These backtraces from mieqEnqueue may point to a culprit higher up the stack.
(EE) [mi] mieq is *NOT* the cause.  It is a victim.


I would be happy to provider further information if needed or test some workarounds.