[PATCH v2 2/4] drm/xe/guc: WRITE_ONCE g2h_fence done in parse_g2h_response

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

Use WRITE_ONCE when operating on g2h_fence->done in parse_g2h_response
to prevent the compiler from ignoring this operation.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_ct.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index d177df166d2a..38b58590c94b 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -1500,7 +1500,8 @@ static int parse_g2h_response(struct xe_guc_ct *ct, u32 *msg, u32 len)
 
 	g2h_release_space(ct, GUC_CTB_HXG_MSG_MAX_LEN);
 
-	g2h_fence->done = true;
+	/* WRITE_ONCE pairs with wait_event_timeout in guc_ct_send_recv */
+	WRITE_ONCE(g2h_fence->done, true);
 	smp_mb();
 
 	wake_up_all(&ct->g2h_fence_wq);
-- 
2.43.0