drm/radeon: work around a hw bug in MGCG on CIK
Always need to set bit 0 of RLC_CGTT_MGCG_OVERRIDE
to avoid unreliable doorbell updates in some cases.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index bce73b6..cef4cb7 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -6344,6 +6344,7 @@
}
orig = data = RREG32(RLC_CGTT_MGCG_OVERRIDE);
+ data |= 0x00000001;
data &= 0xfffffffd;
if (orig != data)
WREG32(RLC_CGTT_MGCG_OVERRIDE, data);
@@ -6377,7 +6378,7 @@
}
} else {
orig = data = RREG32(RLC_CGTT_MGCG_OVERRIDE);
- data |= 0x00000002;
+ data |= 0x00000003;
if (orig != data)
WREG32(RLC_CGTT_MGCG_OVERRIDE, data);