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

alexdeucher · gregkh · commit 14172f8e9485 · 2025-01-02T10:32:08.000+01:00
[ Upstream commit abe1cba ] Need to read back to make sure the write goes through. Cc: David Belanger <david.belanger@amd.com> Reviewed-by: Frank Min <frank.min@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/gpu/drm/amd/amdgpu/hdp_v6_0.c b/drivers/gpu/drm/amd/amdgpu/hdp_v6_0.c
@@ -31,10 +31,12 @@
 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
`@@ -31,10 +31,12 @@`
`31`	`31`	`static void hdp_v6_0_flush_hdp(struct amdgpu_device *adev,`
`32`	`32`	`struct amdgpu_ring *ring)`
`33`	`33`	`{`
`34`		`- if (!ring \|\| !ring->funcs->emit_wreg)`
	`34`	`+ if (!ring \|\| !ring->funcs->emit_wreg) {`
`35`	`35`	`WREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);`
`36`		`- else`
	`36`	`+ RREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2);`
	`37`	`+ } else {`
`37`	`38`	`amdgpu_ring_emit_wreg(ring, (adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);`
	`39`	`+ }`
`38`	`40`	`}`
`39`	`41`
`40`	`42`	`static void hdp_v6_0_update_clock_gating(struct amdgpu_device *adev,`