drm/xe/guc_submit: fix race around pending_disable

Currently in some testcases we can trigger:

[drm] *ERROR* GT0: SCHED_DONE: Unexpected engine state 0x02b1, guc_id=8, runnable_state=0
[drm] *ERROR* GT0: G2H action 0x1002 failed (-EPROTO) len 3 msg 02 10 00 90 08 00 00 00 00 00 00 00

Looking at a snippet of corresponding ftrace for this GuC id we can see:

498.852891: xe_sched_msg_add:     dev=0000:03:00.0, gt=0 guc_id=8, opcode=3
498.854083: xe_sched_msg_recv:    dev=0000:03:00.0, gt=0 guc_id=8, opcode=3
498.855389: xe_exec_queue_kill:   dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x3, flags=0x0
498.855436: xe_exec_queue_lr_cleanup: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x83, flags=0x0
498.856767: xe_exec_queue_close:  dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x83, flags=0x0
498.862889: xe_exec_queue_scheduling_disable: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0xa9, flags=0x0
498.863032: xe_exec_queue_scheduling_disable: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x2b9, flags=0x0
498.875596: xe_exec_queue_scheduling_done: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x2b9, flags=0x0
498.875604: xe_exec_queue_deregister: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x2b1, flags=0x0
499.074483: xe_exec_queue_deregister_done: dev=0000:03:00.0, 5:0x1, gt=0, width=1, guc_id=8, guc_state=0x2b1, flags=0x0

This looks to be the two scheduling_disable racing with each other, one
from the suspend (opcode=3) and then again during lr cleanup. While
those two operations are serialized, the G2H portion is not, therefore
when marking the queue as pending_disabled and then firing off the first
request, we proceed do the same again, however the first disable
response only fires after this which then clears the pending_disabled.
At this point the second comes back and is processed, however the
pending_disabled is no longer set, hence triggering the warning.

To fix this wait for pending_disabled when doing the lr cleanup and
calling disable_scheduling_deregister. Also do the same for all other
disable_scheduling callers.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3515
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger.kernel.org> # v6.8+
Reviewed-by: Matthew Brost <mattheq.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241122161914.321263-5-matthew.auld@intel.com
(cherry picked from commit ddb106d2120a0bf1c5ff87c71d059d193814da41)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

0 files changed, 0 insertions, 0 deletions