drm/amdgpu/hdp6.0: do a posting read when flushing HDP

alexdeucher · alexdeucher · commit abe1cbaec6cf · 2024-12-02T17:38:47.000-05:00
Need to read back to make sure the write goes through.

Cc: David Belanger &lt;david.belanger@amd.com&gt;
Reviewed-by: Frank Min &lt;frank.min@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/amdgpu/hdp_v6_0.c b/drivers/gpu/drm/amd/amdgpu/hdp_v6_0.c
@@ -34,10 +34,12 @@
 static void hdp_v6_0_flush_hdp(struct amdgpu_device *adev,
 				struct amdgpu_ring *ring)
 {
-	if (!ring || !ring->funcs->emit_wreg)
+	if (!ring || !ring->funcs->emit_wreg) {
 		WREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);
-	else
+		RREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2);
+	} else {
 		amdgpu_ring_emit_wreg(ring, (adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);
+	}
 }
 
 static void hdp_v6_0_update_clock_gating(struct amdgpu_device *adev,

Original file line number	Diff line number	Diff line change
`@@ -34,10 +34,12 @@`
`34`	`34`	`static void hdp_v6_0_flush_hdp(struct amdgpu_device *adev,`
`35`	`35`	`struct amdgpu_ring *ring)`
`36`	`36`	`{`
`37`		`- if (!ring \|\| !ring->funcs->emit_wreg)`
	`37`	`+ if (!ring \|\| !ring->funcs->emit_wreg) {`
`38`	`38`	`WREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);`
`39`		`- else`
	`39`	`+ RREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2);`
	`40`	`+ } else {`
`40`	`41`	`amdgpu_ring_emit_wreg(ring, (adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);`
	`42`	`+ }`
`41`	`43`	`}`
`42`	`44`
`43`	`45`	`static void hdp_v6_0_update_clock_gating(struct amdgpu_device *adev,`