From: jsg <jsg@openbsd.org>
Date: Mon, 5 Sep 2022 14:22:58 +0000 (+0000)
Subject: drm/amd/display: avoid doing vm_init multiple time
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=9e61ec965a34e63e180a8b13289ba4d4a03305c5;p=openbsd

drm/amd/display: avoid doing vm_init multiple time

From Charlene Liu
85dd24ff77c15f5fc0e16bc3f288f5d1ac93e02b in linux 5.15.y/5.15.65
5544a7b5a07480192eb5fd3536462faed2c21528 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/display/dc/dcn21/dcn21_hubbub.c b/sys/dev/pci/drm/amd/display/dc/dcn21/dcn21_hubbub.c
index 36044cb8ec8..1c0f56d8ba8 100644
--- a/sys/dev/pci/drm/amd/display/dc/dcn21/dcn21_hubbub.c
+++ b/sys/dev/pci/drm/amd/display/dc/dcn21/dcn21_hubbub.c
@@ -67,9 +67,15 @@ static uint32_t convert_and_clamp(
 void dcn21_dchvm_init(struct hubbub *hubbub)
 {
 	struct dcn20_hubbub *hubbub1 = TO_DCN20_HUBBUB(hubbub);
-	uint32_t riommu_active;
+	uint32_t riommu_active, prefetch_done;
 	int i;
 
+	REG_GET(DCHVM_RIOMMU_STAT0, HOSTVM_PREFETCH_DONE, &prefetch_done);
+
+	if (prefetch_done) {
+		hubbub->riommu_active = true;
+		return;
+	}
 	//Init DCHVM block
 	REG_UPDATE(DCHVM_CTRL0, HOSTVM_INIT_REQ, 1);