drm/amd/display: avoid doing vm_init multiple time

[ Upstream commit 5544a7b5a07480192eb5fd3536462faed2c21528 ]

[why]
this is to ensure that driver will not reprogram hvm_prefetch_req again if
it is done.

Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hubbub.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hubbub.c
index c5e200d09038fba2cf7cfc1eb3ceba438ed33fa9..5752271f22dfedda223a7feabdbaeb0b37047505 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hubbub.c
+++ b/drivers/gpu/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);