drm/amdgpu: Unset baco dummy mode on nbio v7.9

BACO dummy mode could be set under reset conditions and that affects
framebuffer access. Check If baco dummy mode is set, unset it if so.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Le Ma <le.ma@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Asad Kamal <asad.kamal@amd.com>
Tested-by: Asad Kamal <asad.kamal@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Lijo Lazar

drivers/gpu/drm/amd/amdgpu/nbio_v7_9.c

@@ -437,6 +437,24 @@ static void nbio_v7_9_init_registers(struct amdgpu_device *adev)
 			XCC_DOORBELL_FENCE__SHUB_SLV_MODE_MASK);
 
 	}
+
+	if (!amdgpu_sriov_vf(adev)) {
+		u32 baco_cntl;
+		for_each_inst(i, adev->aid_mask) {
+			baco_cntl = RREG32_SOC15(NBIO, i, regBIF_BX0_BACO_CNTL);
+			if (baco_cntl & (BIF_BX0_BACO_CNTL__BACO_DUMMY_EN_MASK |
+					 BIF_BX0_BACO_CNTL__BACO_EN_MASK)) {
+				baco_cntl &= ~(
+					BIF_BX0_BACO_CNTL__BACO_DUMMY_EN_MASK |
+					BIF_BX0_BACO_CNTL__BACO_EN_MASK);
+				dev_dbg(adev->dev,
+					"Unsetting baco dummy mode %x",
+					baco_cntl);
+				WREG32_SOC15(NBIO, i, regBIF_BX0_BACO_CNTL,
+					     baco_cntl);
+			}
+		}
+	}
 }
 
 static u64 nbio_v7_9_get_pcie_replay_count(struct amdgpu_device *adev)