drm/amdgpu/hdp7: use memcfg register to post the write for HDP flush

commit 5a11a2767731139bf87e667331aa2209e33a1d19 upstream.

Reading back the remapped HDP flush register seems to cause
problems on some platforms. All we need is a read, so read back
the memcfg register.

Fixes: 689275140cb8 ("drm/amdgpu/hdp7.0: do a posting read when flushing HDP")
Reported-by: Alexey Klimov <alexey.klimov@linaro.org>
Link: https://lists.freedesktop.org/archives/amd-gfx/2025-April/123150.html
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4119
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3908
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit dbc064adfcf9095e7d895bea87b2f75c1ab23236)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alex Deucher
2025-04-30 12:50:02 -04:00
committed by Greg Kroah-Hartman
parent df04418262
commit 92d0a28afb

View File

@@ -33,7 +33,12 @@ static void hdp_v7_0_flush_hdp(struct amdgpu_device *adev,
{
if (!ring || !ring->funcs->emit_wreg) {
WREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);
RREG32((adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2);
/* We just need to read back a register to post the write.
* Reading back the remapped register causes problems on
* some platforms so just read back the memory size register.
*/
if (adev->nbio.funcs->get_memsize)
adev->nbio.funcs->get_memsize(adev);
} else {
amdgpu_ring_emit_wreg(ring, (adev->rmmio_remap.reg_offset + KFD_MMIO_REMAP_HDP_MEM_FLUSH_CNTL) >> 2, 0);
}