Hello Xiangliang Yu,
The patch bc992ba5a3c1: "drm/amdgpu/virt: use kiq to access registers
(v2)" from Jan 12, 2017, leads to the following static checker
warning:
drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c:122 amdgpu_virt_kiq_rreg()
error: uninitialized symbol 'f'.
drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
104 uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg)
105 {
106 signed long r;
107 uint32_t val;
108 struct dma_fence *f;
109 struct amdgpu_kiq *kiq = &adev->gfx.kiq;
110 struct amdgpu_ring *ring = &kiq->ring;
111
112 BUG_ON(!ring->funcs->emit_rreg);
113
114 mutex_lock(&adev->virt.lock);
115 amdgpu_ring_alloc(ring, 32);
116 amdgpu_ring_emit_hdp_flush(ring);
117 amdgpu_ring_emit_rreg(ring, reg);
118 amdgpu_ring_emit_hdp_invalidate(ring);
119 amdgpu_fence_emit(ring, &f);
What about if amdgpu_fence_emit() returns -ENOMEM?
120 amdgpu_ring_commit(ring);
121 mutex_unlock(&adev->virt.lock);
122
123 r = dma_fence_wait(f, false);
124 if (r)
125 DRM_ERROR("wait for kiq fence error: %ld.\n", r);
126 dma_fence_put(f);
127
128 val = adev->wb.wb[adev->virt.reg_val_offs];
129
130 return val;
131 }
regards,
dan carpenter
