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| author | David (Ming Qiang) Wu <David.Wu3@amd.com> | 2025-05-15 01:56:35 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2025-05-29 17:56:14 +0300 |
| commit | 4d4275a0387790fbe0a016c075dcbb39d58b63ab (patch) | |
| tree | c7cc3dc00f69a07a9fe43dd35103b5fea167af0f | |
| parent | 5b4c6413c89613cb46669b576d83658fe6e734da (diff) | |
| download | linux-4d4275a0387790fbe0a016c075dcbb39d58b63ab.tar.xz | |
drm/amdgpu/vcn4.0.5: read back register after written
The addition of register read-back in VCN v4.0.5 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_v4_0_5.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c index a09f9a2dd471..16ade84facc7 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c @@ -1254,6 +1254,11 @@ static void vcn_v4_0_5_stop_dpg_mode(struct amdgpu_vcn_inst *vinst) /* disable dynamic power gating mode */ WREG32_P(SOC15_REG_OFFSET(VCN, inst_idx, 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, inst_idx, regUVD_STATUS); } /** @@ -1337,6 +1342,11 @@ static int vcn_v4_0_5_stop(struct amdgpu_vcn_inst *vinst) /* enable VCN power gating */ vcn_v4_0_5_enable_static_power_gating(vinst); + /* Keeping one read-back to ensure all register writes are done, + * otherwise it may introduce race conditions. + */ + RREG32_SOC15(VCN, i, regUVD_STATUS); + done: if (adev->pm.dpm_enabled) amdgpu_dpm_enable_vcn(adev, false, i); |