[PATCH 1/6] drm/xe/xe_guc_ct: WRITE_ONCE g2h_fence done in g2h_fence_cancel

[Jonathan Cavitt <jonathan.cavitt@intel.com>]

Use WRITE_ONCE when operating on g2h_fence->done in g2h_fence_cancel to
prevent the compiler from ignoring this operation.

Fixes: 94de94d24ea8 ("drm/xe/guc: Cancel ongoing H2G requests when stopping CT")
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_ct.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index c3df9b3f1b4d..d177df166d2a 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -206,7 +206,9 @@ static void g2h_fence_cancel(struct g2h_fence *g2h_fence)
 {
 	g2h_fence->cancel = true;
 	g2h_fence->fail = true;
-	g2h_fence->done = true;
+
+	/* WRITE_ONCE pairs with wait_event_timeout in guc_ct_send_recv */
+	WRITE_ONCE(g2h_fence->done, true);
 }
 
 static bool g2h_fence_needs_alloc(struct g2h_fence *g2h_fence)
-- 
2.43.0