Comment 58 for bug 1201528

After booting 3.9.0-030900rc1 could not login to desktop session, keep getting constant kernel panics, apparently caused by nouveau module. From /var/log/kern.log:

Aug 6 16:28:55 dale kernel: [ 48.092580] traps: gdu-notificatio[1878] trap int3 ip:7f9e5cda4fdb sp:7fff193ca1b0 error:0
Aug 6 16:28:57 dale kernel: [ 49.249223] nouveau E[ PFB][0000:01:00.0] trapped read at 0x002001e020 on channel 0x0001fb24 [unknown] SEMAPHORE_BG/PFIFO_READ/00 reason: PAGE_NOT_PRESENT
Aug 6 16:28:57 dale kernel: [ 49.249326] nouveau E[ PFIFO][0000:01:00.0] CACHE_ERROR - ch 2 [Xorg[1070]] subc 0 mthd 0x0060 data 0xbeef0201
Aug 6 16:28:57 dale kernel: [ 49.252849] nouveau E[ PGRAPH][0000:01:00.0] TRAP_M2MF NOTIFY
Aug 6 16:28:57 dale kernel: [ 49.252885] nouveau E[ PGRAPH][0000:01:00.0] TRAP_M2MF 00304041 00004360 00000000 06000432
Aug 6 16:28:57 dale kernel: [ 49.252916] nouveau E[ PGRAPH][0000:01:00.0] TRAP
Aug 6 16:28:57 dale kernel: [ 49.252946] nouveau E[ PGRAPH][0000:01:00.0] ch 2 [0x001fb24000 Xorg[1070]] subc 0 class 0x5039 mthd 0x0328 data 0x00000000
Aug 6 16:28:57 dale kernel: [ 49.252994] nouveau E[ PFB][0000:01:00.0] trapped write at 0x002001e010 on channel 0x0001fb24 [Xorg[1070]] PGRAPH/DISPATCH/M2M_NOTIFY reason: PAGE_NOT_PRESENT
Aug 6 16:28:57 dale kernel: [ 49.253088] nouveau E[ PGRAPH][0000:01:00.0] TRAP_M2MF IN
Aug 6 16:28:57 dale kernel: [ 49.253124] nouveau E[ PGRAPH][0000:01:00.0] TRAP_M2MF 003200d1 2039a980 00000000 04000000
Aug 6 16:28:57 dale kernel: [ 49.253154] nouveau E[ PGRAPH][0000:01:00.0] TRAP
Aug 6 16:28:57 dale kernel: [ 49.253184] nouveau E[ PGRAPH][0000:01:00.0] ch 2 [0x001fb24000 Xorg[1070]] subc 0 class 0x5039 mthd 0x0328 data 0x00000000
Aug 6 16:29:18 dale kernel: [ 70.935563] nouveau E[ PFB][0000:01:00.0] trapped read at 0x002001e020 on channel 0x0001fb24 [unknown] SEMAPHORE_BG/PFIFO_READ/00 reason: PAGE_NOT_PRESENT
Aug 6 16:29:19 dale kernel: [ 71.300930] traps: gdu-notificatio[2198] trap int3 ip:7fc07ed52fdb sp:7fffc5051b40 error:0
Aug 6 16:29:21 dale kernel: [ 73.932288] nouveau E[Xorg[1894]] failed to idle channel 0xcccc0000 [Xorg[1894]]
Aug 6 16:29:21 dale kernel: [ 73.932340] nouveau E[ PFB][0000:01:00.0] trapped read at 0x002001c100 on channel 0x0001fb24 [unknown] SEMAPHORE_BG/PFIFO_READ/00 reason: PAGE_NOT_PRESENT
Aug 6 16:29:21 dale kernel: [ 73.932732] nouveau E[ PGRAPH][0000:01:00.0] TRAP_DISPATCH (unknown 0x00000004)
Aug 6 16:29:21 dale kernel: [ 73.932828] nouveau E[ PFB][0000:01:00.0] trapped read at 0x0000000000 on channel 0x0001fb24 [Xorg[1894]] PGRAPH/DISPATCH/GRCTX reason: DMAOBJ_LIMIT
Aug 6 16:29:21 dale kernel: [ 73.932915] nouveau E[ PGRAPH][0000:01:00.0] ILLEGAL_MTHD ILLEGAL_CLASS
Aug 6 16:29:21 dale kernel: [ 73.932951] nouveau E[ PGRAPH][0000:01:00.0] ch -1 [0x001fb24000 unknown] subc 2 class 0x0000 mthd 0x0200 data 0x000000cf

(a LOT more errors like the above).