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authorXiaojie Yuan <xiaojie.yuan@amd.com>2020-07-14 15:47:31 +0800
committerAlex Deucher <alexander.deucher@amd.com>2020-07-14 15:42:17 -0400
commit05051496b2622e4d12e2036b35165969aa502f89 (patch)
tree772b65efe21dc07bf473e1ce65527acabb433bc7
parent98a34cf931e848f8489d3fb15a8f5fc03802ad65 (diff)
drm/amdgpu/sdma5: fix wptr overwritten in ->get_wptr()amd-drm-fixes-5.8-2020-07-15
"u64 *wptr" points to the the wptr value in write back buffer and "*wptr = (*wptr) >> 2;" results in the value being overwritten each time when ->get_wptr() is called. umr uses /sys/kernel/debug/dri/0/amdgpu_ring_sdma0 to get rptr/wptr and decode ring content and it is affected by this issue. fix and simplify the logic similar as sdma_v4_0_ring_get_wptr(). v2: fix for sdma5.2 as well v3: drop sdma 5.2 changes for 5.8 and stable Suggested-by: Le Ma <le.ma@amd.com> Signed-off-by: Xiaojie Yuan <xiaojie.yuan@amd.com> Reviewed-by: Christian K├Ânig <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c26
1 files changed, 8 insertions, 18 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c
index 5d71c23e2640..8fb66e50a57b 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c
@@ -314,30 +314,20 @@ static uint64_t sdma_v5_0_ring_get_rptr(struct amdgpu_ring *ring)
static uint64_t sdma_v5_0_ring_get_wptr(struct amdgpu_ring *ring)
{
struct amdgpu_device *adev = ring->adev;
- u64 *wptr = NULL;
- uint64_t local_wptr = 0;
+ u64 wptr;
if (ring->use_doorbell) {
/* XXX check if swapping is necessary on BE */
- wptr = ((u64 *)&adev->wb.wb[ring->wptr_offs]);
- DRM_DEBUG("wptr/doorbell before shift == 0x%016llx\n", *wptr);
- *wptr = (*wptr) >> 2;
- DRM_DEBUG("wptr/doorbell after shift == 0x%016llx\n", *wptr);
+ wptr = READ_ONCE(*((u64 *)&adev->wb.wb[ring->wptr_offs]));
+ DRM_DEBUG("wptr/doorbell before shift == 0x%016llx\n", wptr);
} else {
- u32 lowbit, highbit;
-
- wptr = &local_wptr;
- lowbit = RREG32(sdma_v5_0_get_reg_offset(adev, ring->me, mmSDMA0_GFX_RB_WPTR)) >> 2;
- highbit = RREG32(sdma_v5_0_get_reg_offset(adev, ring->me, mmSDMA0_GFX_RB_WPTR_HI)) >> 2;
-
- DRM_DEBUG("wptr [%i]high== 0x%08x low==0x%08x\n",
- ring->me, highbit, lowbit);
- *wptr = highbit;
- *wptr = (*wptr) << 32;
- *wptr |= lowbit;
+ wptr = RREG32(sdma_v5_0_get_reg_offset(adev, ring->me, mmSDMA0_GFX_RB_WPTR_HI));
+ wptr = wptr << 32;
+ wptr |= RREG32(sdma_v5_0_get_reg_offset(adev, ring->me, mmSDMA0_GFX_RB_WPTR));
+ DRM_DEBUG("wptr before shift [%i] wptr == 0x%016llx\n", ring->me, wptr);
}
- return *wptr;
+ return wptr >> 2;
}
/**