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 36044cb..1c0f56d 100644 (file)
--- 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);