Ubuntu 12.04.4, ядро 3.5.0-46-generic, стек иксовых пакетов тот же, от lts-quantal, штатный хранитель экрана, карта - Radeon HD3650 (чип RV635). Периодически при выходе из хранителя экрана случается полный подвисон иксов. Вот что было в dmesg в такой ситуации.
[219596.652115] radeon 0000:01:00.0: GPU lockup CP stall for more than 10000msec
[219596.652129] radeon 0000:01:00.0: GPU lockup (waiting for 0x00000000004f95c6 last fence id 0x00000000004f95c3)
[219596.653254] radeon 0000:01:00.0: GPU softreset
[219596.653262] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0xA0002030
[219596.653270] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0x00000003
[219596.653277] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200000C0
[219596.653292] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0x00007FEE
[219596.668185] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0x00000001
[219596.684070] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0xA0003030
[219596.684079] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0x00000003
[219596.684086] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200080C0
[219596.685084] radeon 0000:01:00.0: GPU reset succeed
[219596.690961] [drm] PCIE GART of 512M enabled (table at 0x0000000000040000).
[219596.691019] radeon 0000:01:00.0: WB enabled
[219596.691029] radeon 0000:01:00.0: fence driver on ring 0 use gpu addr 0x0000000040000c00 and cpu addr 0xffff8800b87abc00
[219596.722853] [drm] ring test on 0 succeeded in 0 usecs
[219596.722961] [drm] ib test on ring 0 succeeded in 0 usecs
[219608.832116] radeon 0000:01:00.0: GPU lockup CP stall for more than 10000msec
[219608.832130] radeon 0000:01:00.0: GPU lockup (waiting for 0x00000000004f95ce last fence id 0x00000000004f95ca)
[219608.833248] radeon 0000:01:00.0: GPU softreset
[219608.833256] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0xA2703CE0
[219608.833263] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0x00000103
[219608.833271] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200210C0
[219609.023697] radeon 0000:01:00.0: Wait for MC idle timedout !
[219609.023709] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0x00007FEE
[219609.038601] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0x00000001
[219609.054484] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0xA0003030
[219609.054492] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0x00000003
[219609.054499] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200290C0
[219609.055497] radeon 0000:01:00.0: GPU reset succeed
[219609.232272] radeon 0000:01:00.0: Wait for MC idle timedout !
[219609.405593] radeon 0000:01:00.0: Wait for MC idle timedout !
[219609.407779] [drm] PCIE GART of 512M enabled (table at 0x0000000000040000).
[219609.407808] radeon 0000:01:00.0: WB enabled
[219609.407812] radeon 0000:01:00.0: fence driver on ring 0 use gpu addr 0x0000000040000c00 and cpu addr 0xffff8800b87abc00
[219609.439510] [drm] ring test on 0 succeeded in 0 usecs
[219619.936074] radeon 0000:01:00.0: GPU lockup CP stall for more than 10000msec
[219619.936088] radeon 0000:01:00.0: GPU lockup (waiting for 0x00000000004f95d1 last fence id 0x00000000004f95d0)
[219619.936095] [drm:r600_ib_test] *ERROR* radeon: fence wait failed (-35).
[219619.936101] [drm:radeon_ib_ring_tests] *ERROR* radeon: failed testing IB on GFX ring (-35).
[219619.936107] [drm:r600_resume] *ERROR* r600 startup failed on resume
Может есть идеи в чем причина и как полечить?