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| author | David (Ming Qiang) Wu <David.Wu3@amd.com> | 2025-05-15 01:59:11 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2025-05-29 17:56:19 +0300 |
| commit | bf394d28548c3c0a01e113fdef20ddb6cd2df106 (patch) | |
| tree | 4896d1b86b7c9bd8ef91aaf7d281294c09de0fee | |
| parent | a8bce9b7a2ccb5cbbe9967a37e617a9ef963e540 (diff) | |
| download | linux-bf394d28548c3c0a01e113fdef20ddb6cd2df106.tar.xz | |
drm/amdgpu/vcn5.0.1: read back register after written
The addition of register read-back in VCN v5.0.1 is intended to prevent
potential race conditions.
Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Signed-off-by: David (Ming Qiang) Wu <David.Wu3@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c b/drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c index 1e9d2aedf279..338cf43c45fe 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c @@ -1038,6 +1038,11 @@ static int vcn_v5_0_1_start(struct amdgpu_vcn_inst *vinst) WREG32_SOC15(VCN, vcn_inst, regVCN_RB_ENABLE, tmp); fw_shared->sq.queue_mode &= ~(FW_QUEUE_RING_RESET | FW_QUEUE_DPG_HOLD_OFF); + /* Keeping one read-back to ensure all register writes are done, + * otherwise it may introduce race conditions. + */ + RREG32_SOC15(VCN, vcn_inst, regUVD_STATUS); + return 0; } @@ -1072,6 +1077,11 @@ static void vcn_v5_0_1_stop_dpg_mode(struct amdgpu_vcn_inst *vinst) /* disable dynamic power gating mode */ WREG32_P(SOC15_REG_OFFSET(VCN, vcn_inst, regUVD_POWER_STATUS), 0, ~UVD_POWER_STATUS__UVD_PG_MODE_MASK); + + /* Keeping one read-back to ensure all register writes are done, + * otherwise it may introduce race conditions. + */ + RREG32_SOC15(VCN, vcn_inst, regUVD_STATUS); } /** @@ -1147,6 +1157,11 @@ static int vcn_v5_0_1_stop(struct amdgpu_vcn_inst *vinst) /* clear status */ WREG32_SOC15(VCN, vcn_inst, regUVD_STATUS, 0); + /* Keeping one read-back to ensure all register writes are done, + * otherwise it may introduce race conditions. + */ + RREG32_SOC15(VCN, vcn_inst, regUVD_STATUS); + return 0; } |