r445 wedge hard re-arm experiment (gsp_phys_gr_wedge_rearm, default off): on the proven engine-wedged warm-sem-probe failure, one bounded recovery attempt - TSG PREEMPT bWait=1 (forced context save/unload) + the m155 extended re-arm (mode-35 lane-enable tail + GPFIFO schedules + doorbell) + a repeated probe - before the historical WEDGED break

1 files changed, 24 insertions, 0 deletions

diff --git a/kernel/gsp_phys_gpu.c b/kernel/gsp_phys_gpu.c
index eadb4c2..b61929e 100644
--- a/kernel/gsp_phys_gpu.c
+++ b/kernel/gsp_phys_gpu.c
@@ -1174,6 +1174,30 @@ int gsp_phys_gr_nowrite_retries_value(void)
 EXPORT_SYMBOL_GPL(gsp_phys_gr_nowrite_retries_value);
 
 /*
+ * r445 wedge hard re-arm (gsp_phys_gr_wedge_rearm; default 0 = off). When the
+ * outcome-retry's warm GR semaphore probe proves the engine wedged for the
+ * context (the proven-sticky post-dispatch no-store state), this knob makes
+ * the submit attempt ONE bounded recovery instead of breaking immediately:
+ * a TSG PREEMPT(bWait=1) forces the FECS to save/unload the channel's
+ * context, then the mode-35 lane-enable tail + GPFIFO schedules are re-issued
+ * (the m155 extended re-arm) and the semaphore probe is repeated. A pass
+ * means the lane revived for this launch and the normal retry ladder
+ * continues; a fail leaves the historical WEDGED break. Read once per wedge
+ * episode. Off by default for A/B.
+ */
+static int gsp_phys_gr_wedge_rearm_param;
+module_param_named(gsp_phys_gr_wedge_rearm, gsp_phys_gr_wedge_rearm_param,
+		   int, 0644);
+MODULE_PARM_DESC(gsp_phys_gr_wedge_rearm,
+		 "r445: on the proven engine-wedged sem probe, attempt a bounded preempt+resched hard re-arm before giving up (default 0=off)");
+
+int gsp_phys_gr_wedge_rearm_value(void)
+{
+	return gsp_phys_gr_wedge_rearm_param ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(gsp_phys_gr_wedge_rearm_value);
+
+/*
  * r410 wedge quiet window (gsp_phys_gr_wedge_quiet_ms; default 40000, clamped
  * [0,120000]; 0 disables). The sticky per-lane no-execute wedge (100% of
  * launches no-write while kept busy) is proven to CLEAR when the lane stays