[PATCH] drm/radeon: fix a semaphore deadlock on pre cayman asics

[Christian König]

The out of order execution of semaphore commands on
pre cayman asics doesn't work correctly and can
cause deadlocks, so turn it off for now.

Signed-off-by: Christian König <deathsimple at vodafone.de>
---
 drivers/gpu/drm/radeon/r600.c  |    3 +++
 drivers/gpu/drm/radeon/r600d.h |    1 +
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 8a6d68c..f0b3323 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2362,6 +2362,9 @@ void r600_semaphore_ring_emit(struct radeon_device *rdev,
 	uint64_t addr = semaphore->gpu_addr;
 	unsigned sel = emit_wait ? PACKET3_SEM_SEL_WAIT : PACKET3_SEM_SEL_SIGNAL;
 
+	if (rdev->family < CHIP_CAYMAN)
+		sel |= PACKET3_SEM_WAIT_ON_SIGNAL;
+
 	radeon_ring_write(ring, PACKET3(PACKET3_MEM_SEMAPHORE, 1));
 	radeon_ring_write(ring, addr & 0xffffffff);
 	radeon_ring_write(ring, (upper_32_bits(addr) & 0xff) | sel);
diff --git a/drivers/gpu/drm/radeon/r600d.h b/drivers/gpu/drm/radeon/r600d.h
index 2ba460b..8ae328f 100644
--- a/drivers/gpu/drm/radeon/r600d.h
+++ b/drivers/gpu/drm/radeon/r600d.h
@@ -850,6 +850,7 @@
 #define	PACKET3_STRMOUT_BUFFER_UPDATE			0x34
 #define	PACKET3_INDIRECT_BUFFER_MP			0x38
 #define	PACKET3_MEM_SEMAPHORE				0x39
+#              define PACKET3_SEM_WAIT_ON_SIGNAL    (0x1 << 12)
 #              define PACKET3_SEM_SEL_SIGNAL	    (0x6 << 29)
 #              define PACKET3_SEM_SEL_WAIT	    (0x7 << 29)
 #define	PACKET3_MPEG_INDEX				0x3A
-- 
1.7.5.4