Instead of declaring pointers use READ_ONCE(), when accessing those values to make sure that the compiler doesn't voilate any cache coherences
Cc: Guchun Chen <[email protected]> Cc: Christian König <[email protected]> Cc: Alex Deucher <[email protected]> Cc: "Pan, Xinhui" <[email protected]> Cc: Le Ma <[email protected]> Cc: Hawking Zhang <[email protected]> Signed-off-by: Srinivasan Shanmugam <[email protected]> --- drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c index f413898dda37..267c1b7b8dcd 100644 --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c @@ -154,13 +154,13 @@ static int sdma_v4_4_2_init_microcode(struct amdgpu_device *adev) */ static uint64_t sdma_v4_4_2_ring_get_rptr(struct amdgpu_ring *ring) { - u64 *rptr; + u64 rptr; /* XXX check if swapping is necessary on BE */ - rptr = ((u64 *)&ring->adev->wb.wb[ring->rptr_offs]); + rptr = READ_ONCE(*((u64 *)&ring->adev->wb.wb[ring->rptr_offs])); - DRM_DEBUG("rptr before shift == 0x%016llx\n", *rptr); - return ((*rptr) >> 2); + DRM_DEBUG("rptr before shift == 0x%016llx\n", rptr); + return rptr >> 2; } /** -- 2.25.1
