drm/radeon: Sync ME and PFP after CP semaphore waits v4
Fixes lockups due to CP read GPUVM faults when running piglit on Cape
Verde.
v2 (chk): apply the fix to R600+ as well, on CIK only the GFX CP has
a PFP, add more comments to R600 code, enable flushing again
v3: (agd5f): only apply to 7xx+. r6xx does not have the packet.
v4: (agd5f): split flush change into a separate patch, fix formatting
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index d61bc18..af2cbc6 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -3920,6 +3920,17 @@
radeon_ring_write(ring, 0);
}
+/**
+ * cik_semaphore_ring_emit - emit a semaphore on the CP ring
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon ring buffer object
+ * @semaphore: radeon semaphore object
+ * @emit_wait: Is this a sempahore wait?
+ *
+ * Emits a semaphore signal/wait packet to the CP ring and prevents the PFP
+ * from running ahead of semaphore waits.
+ */
bool cik_semaphore_ring_emit(struct radeon_device *rdev,
struct radeon_ring *ring,
struct radeon_semaphore *semaphore,
@@ -3932,6 +3943,12 @@
radeon_ring_write(ring, lower_32_bits(addr));
radeon_ring_write(ring, (upper_32_bits(addr) & 0xffff) | sel);
+ if (emit_wait && ring->idx == RADEON_RING_TYPE_GFX_INDEX) {
+ /* Prevent the PFP from running ahead of the semaphore wait */
+ radeon_ring_write(ring, PACKET3(PACKET3_PFP_SYNC_ME, 0));
+ radeon_ring_write(ring, 0x0);
+ }
+
return true;
}