[PATCH 2/3] drm/xe/guc: Wait before retrying sending H2G

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

We shall resend H2G message after receiving NO_RESPONSE_RETRY reply,
but since GuC dropped that H2G due to some interim state, we should
give it a little time to stabilize. Wait before sending the same H2G
again, start with 1ms delay, then increasing it up to 1s.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/xe_guc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index 2a3b057fc828..3ba0ea015611 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -1397,6 +1397,7 @@ int xe_guc_mmio_send_recv(struct xe_guc *guc, const u32 *request,
 	struct xe_reg reply_reg = xe_gt_is_media_type(gt) ?
 		MED_VF_SW_FLAG(0) : VF_SW_FLAG(0);
 	const u32 LAST_INDEX = VF_SW_FLAG_COUNT - 1;
+	unsigned int sleep_period_ms = 1;
 	bool lost = false;
 	u32 header;
 	int ret;
@@ -1477,8 +1478,12 @@ int xe_guc_mmio_send_recv(struct xe_guc *guc, const u32 *request,
 	    GUC_HXG_TYPE_NO_RESPONSE_RETRY) {
 		u32 reason = FIELD_GET(GUC_HXG_RETRY_MSG_0_REASON, header);
 
-		xe_gt_dbg(gt, "GuC mmio request %#x: retrying, reason %#x\n",
-			  request[0], reason);
+		xe_gt_dbg(gt, "GuC mmio request %#x: retrying after %u ms, reason %#x\n",
+			  request[0], sleep_period_ms, reason);
+
+		msleep(sleep_period_ms);
+		if (sleep_period_ms < 1024)
+			sleep_period_ms <<= 1;
 		goto retry;
 	}
 
-- 
2.47.1