[PATCH v2 2/5] drm/xe/vf: Avoid LRC being freed while applying fixups

[Tomasz Lis <tomasz.lis@intel.com>]

There is a small but non-zero chance that fixups are running on
a context during teardown. The chances are decreased by starting
the teardown by releasing guc_id, but remain non-zero.
On the other hand the sync between fixups and context creation
drastically increases chance for such parallel teardown if
context creation fails.

Prevent LRC teardown in parallel with fixups by getting a reference.

Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
---
 drivers/gpu/drm/xe/xe_exec_queue.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
index 42849be46166..e9396ad3390a 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.c
+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
@@ -1669,10 +1669,11 @@ int xe_exec_queue_contexts_hwsp_rebase(struct xe_exec_queue *q, void *scratch)
 		lrc = READ_ONCE(q->lrc[i]);
 		if (!lrc)
 			continue;
-
+		xe_lrc_get(lrc);
 		xe_lrc_update_memirq_regs_with_address(lrc, q->hwe, scratch);
 		xe_lrc_update_hwctx_regs_with_address(lrc);
 		err = xe_lrc_setup_wa_bb_with_scratch(lrc, q->hwe, scratch);
+		xe_lrc_put(lrc);
 		if (err)
 			break;
 	}
-- 
2.25.1