[PATCH 5.19 58/72] drm/amd/display: avoid doing vm_init multiple time

Greg Kroah-Hartman
2022-09-02T12:54:33Z

From: Charlene Liu <Charlene.Liu@amd.com>

[ 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>
---
drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hubbub.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

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 c5e200d09038f..5752271f22dfe 100644
--- 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);

--
2.35.1