[PATCH 5/5] drm/amdgpu/hdp7.0: do a posting read when flushing HDP

[Min, Frank]

[AMD Official Use Only - AMD Internal Distribution Only]

Hi Alex,
These serial patches look good to me.

Reviewed-By: Frank.Min at amd.com

Best Regards,
Frank

-----Original Message-----
From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Alex Deucher
Sent: Saturday, November 23, 2024 12:27 AM
To: amd-gfx at lists.freedesktop.org
Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Belanger, David <David.Belanger at amd.com>
Subject: [PATCH 5/5] drm/amdgpu/hdp7.0: do a posting read when flushing HDP

Need to read back to make sure the write goes through.

Cc: David Belanger <david.belanger at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/hdp_v7_0.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/hdp_v7_0.c b/drivers/gpu/drm/amd/amdgpu/hdp_v7_0.c
index 1c99bb09e2a1..63820329f67e 100644
--- a/drivers/gpu/drm/amd/amdgpu/hdp_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/hdp_v7_0.c
@@ -31,10 +31,12 @@
 static void hdp_v7_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_v7_0_update_clock_gating(struct amdgpu_device *adev,
--
2.47.0