[PATCH 3/3] drm/xe/guc/ct: Flush g2h worker in case of g2h response timeout

[Badal Nilawar <badal.nilawar@intel.com>]

In case if g2h worker doesn't get opportunity to within specified
timeout delay then flush the g2h worker explicitly.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/issues/1620
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/issues/2902
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
---
 drivers/gpu/drm/xe/xe_guc_ct.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index dcc95c01b6f0..2e2fa59eadfb 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -1034,6 +1034,18 @@ static int guc_ct_send_recv(struct xe_guc_ct *ct, const u32 *action, u32 len,
 	}
 	mutex_unlock(&ct->lock);
 
+	/*
+	 * Flush g2h_worker explicitly in case if it didn't get opportunity
+	 * to run after it is queued
+	 */
+	if (!ret) {
+		xe_gt_dbg(gt, "Flush G2H worker to service H2G action %#x\n",
+			  action[0]);
+		flush_work(&ct->g2h_worker);
+		if (g2h_fence.done)
+			ret = 1;
+	}
+
 	/*
 	 * Ensure we serialize with completion side to prevent UAF with fence going out of scope on
 	 * the stack, since we have no clue if it will fire after the timeout before we can erase
-- 
2.34.1