Forgot to Cc lkml.
On Mon, 14 Oct 2019, Davidlohr Bueso wrote:
Because it is not a Rmw operation, atomic_set() is never serialized,
and therefore the 'upgradable' smp_mb__{before,after}_atomic() calls
that order the write to preempt_state are completely bogus.
This patch replaces these with smp_mb(), which seems like the
original intent of when the code was written.
Signed-off-by: Davidlohr Bueso <dbu...@suse.de>
---
drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
index 9cf9353a7ff1..d27d8d3208c6 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
@@ -30,10 +30,10 @@ static inline void set_preempt_state(struct a5xx_gpu *gpu,
* preemption or in the interrupt handler so barriers are needed
* before...
*/
- smp_mb__before_atomic();
+ smp_mb();
atomic_set(&gpu->preempt_state, new);
/* ... and after*/
- smp_mb__after_atomic();
+ smp_mb();
}
/* Write the most recent wptr for the given ring into the hardware */
--
2.16.4
