diff options
| author | David (Ming Qiang) Wu <David.Wu3@amd.com> | 2025-05-12 15:14:43 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:11:40 +0100 |
| commit | cef081c8231b52b4a652bbd022e03d80441118be (patch) | |
| tree | ad576b8ad3b88b445c2c76726b3ca87aae724d37 | |
| parent | 9cf5b2a3b72c23fb7b84736d5d19ee6ea718762b (diff) | |
drm/amdgpu: read back register after written for VCN v4.0.5
commit ee7360fc27d6045510f8fe459b5649b2af27811a upstream.
On VCN v4.0.5 there is a race condition where the WPTR is not
updated after starting from idle when doorbell is used. Adding
register read-back after written at function end is to ensure
all register writes are done before they can be used.
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528
Signed-off-by: David (Ming Qiang) Wu <David.Wu3@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 07c9db090b86e5211188e1b351303fbc673378cf)
Cc: stable@vger.kernel.org
(cherry picked from commit ee7360fc27d6045510f8fe459b5649b2af27811a)
Hand modified for contextual changes where there is a for loop
in 6.12 that was dropped later on.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 8 |
1 files changed, 8 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 e0b02bf1c563..3d114ea7049f 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c @@ -985,6 +985,10 @@ static int vcn_v4_0_5_start_dpg_mode(struct amdgpu_device *adev, int inst_idx, b ring->doorbell_index << VCN_RB1_DB_CTRL__OFFSET__SHIFT | VCN_RB1_DB_CTRL__EN_MASK); + /* Keeping one read-back to ensure all register writes are done, otherwise + * it may introduce race conditions */ + RREG32_SOC15(VCN, inst_idx, regVCN_RB1_DB_CTRL); + return 0; } @@ -1167,6 +1171,10 @@ static int vcn_v4_0_5_start(struct amdgpu_device *adev) tmp |= VCN_RB_ENABLE__RB1_EN_MASK; WREG32_SOC15(VCN, i, 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, i, regVCN_RB_ENABLE); } return 0; |