drm/i915: Increase FLR timeout from 3s to 9s

Following the guidelines it takes 3 seconds to perform an FLR
reset. Let's give it a bit more slack because this time can
change depending on the platform and on the firmware
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240523235853.171796-1-andi.shyti@linux.intel.com

drivers/gpu/drm/i915/intel_uncore.c

@@ -2614,11 +2614,18 @@ void intel_uncore_prune_engine_fw_domains(struct intel_uncore *uncore,
 static void driver_initiated_flr(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore->i915;
-	const unsigned int flr_timeout_ms = 3000; /* specs recommend a 3s wait */
+	unsigned int flr_timeout_ms;
 	int ret;
 
 	drm_dbg(&i915->drm, "Triggering Driver-FLR\n");
 
+	/*
+	 * The specification recommends a 3 seconds FLR reset timeout. To be
+	 * cautious, we will extend this to 9 seconds, three times the specified
+	 * timeout.
+	 */
+	flr_timeout_ms = 9000;
+
 	/*
 	 * Make sure any pending FLR requests have cleared by waiting for the
 	 * FLR trigger bit to go to zero. Also clear GU_DEBUG's DRIVERFLR_STATUS