drm/radeon: Clear RB_OVERFLOW bit earlier
Otherwise the bit remains set in rdev->ih.rptr, so the wptr can never
match that and we still have an infinite loop.
This fix allows me to successfully recover from an IH ring buffer
overflow.
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index dbca60c..6a50b03 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -4749,6 +4749,7 @@
wptr = RREG32(IH_RB_WPTR);
if (wptr & RB_OVERFLOW) {
+ wptr &= ~RB_OVERFLOW;
/* When a ring buffer overflow happen start parsing interrupt
* from the last not overwritten vector (wptr + 16). Hopefully
* this should allow us to catchup.
@@ -4759,7 +4760,6 @@
tmp = RREG32(IH_RB_CNTL);
tmp |= IH_WPTR_OVERFLOW_CLEAR;
WREG32(IH_RB_CNTL, tmp);
- wptr &= ~RB_OVERFLOW;
}
return (wptr & rdev->ih.ptr_mask);
}