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/r600.c b/drivers/gpu/drm/radeon/r600.c
index 1e47701..e8bf0ea 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2753,6 +2753,17 @@
}
}
+/**
+ * r600_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 r600_semaphore_ring_emit(struct radeon_device *rdev,
struct radeon_ring *ring,
struct radeon_semaphore *semaphore,
@@ -2768,6 +2779,13 @@
radeon_ring_write(ring, lower_32_bits(addr));
radeon_ring_write(ring, (upper_32_bits(addr) & 0xff) | sel);
+ /* PFP_SYNC_ME packet only exists on 7xx+ */
+ if (emit_wait && (rdev->family >= CHIP_RV770)) {
+ /* 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;
}