Am 26.02.2018 um 06:18 schrieb Monk Liu:
From: Emily Deng <emily.d...@amd.com>
the original method will change the wptr value in wb.
Change-Id: I984fabca35d9dcf1f5fa8ef7779b2afb7f7d7370
Signed-off-by: Emily Deng <emily.d...@amd.com>
---
drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
index 3d5385d..8c6e408 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
@@ -240,13 +240,14 @@ static uint64_t sdma_v4_0_ring_get_wptr(struct
amdgpu_ring *ring)
struct amdgpu_device *adev = ring->adev;
u64 *wptr = NULL;
uint64_t local_wptr = 0;
-
+ u64 tmp = 0;
Please keep an empty line between deceleration and code.
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);
+ tmp = (*wptr) >> 2;
+ DRM_DEBUG("wptr/doorbell after shift == 0x%016llx\n", tmp);
+ return tmp;
Well I completely agree that this code is absolutely nonsense and could
result in complete random hardware behavior.
But I think we need further cleanup than what you already did. How about
the following instead?
static uint64_t sdma_v4_0_ring_get_wptr(struct amdgpu_ring *ring)
{
struct amdgpu_device *adev = ring->adev;
uint64_t wptr;
if (ring->use_doorbell) {
/* XXX check if swapping is necessary on BE */
wptr = READ_ONCE(*((u64 *)&adev->wb.wb[ring->wptr_offs]));
DRM_DEBUG("wptr/doorbell == 0x%016llx\n", *wptr);
} else {
int me = (ring == &adev->sdma.instance[0].ring) ? 0 : 1;
u32 lowbit, highbit;
lowbit = RREG32(sdma_v4_0_get_reg_offset(adev, me,
mmSDMA0_GFX_RB_WPTR));
highbit = RREG32(sdma_v4_0_get_reg_offset(adev, me,
mmSDMA0_GFX_RB_WPTR_HI));
DRM_DEBUG("wptr [%i]high== 0x%08x low==0x%08x\n",
me, highbit, lowbit);
wptr = highbit;
wptr = wptr << 32;
wptr |= lowbit;
}
return wptr >> 2;
}
Good catch,
Christian.
} else {
u32 lowbit, highbit;
int me = (ring == &adev->sdma.instance[0].ring) ? 0 : 1;
@@ -260,9 +261,8 @@ static uint64_t sdma_v4_0_ring_get_wptr(struct amdgpu_ring
*ring)
*wptr = highbit;
*wptr = (*wptr) << 32;
*wptr |= lowbit;
+ return *wptr;
}
-
- return *wptr;
}
/**
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