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drm/amdgpu/sdma5: fix wptr overwritten in ->get_wptr() 

"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 König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Xiaojie Yuan 2020-07-14 15:47:31 +08:00 committed by Alex Deucher
parent 98a34cf931
commit 05051496b2
1 changed files with 8 additions and 18 deletions
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26
drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c
View File

@ -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;
}
/**