> We should only call memset if amdgpu_bo_kmap succeeded. Same issue in patch 2. [ml] agreed >There's something else about these two patches I'm a bit worried about: >The GPU should only read data from ring buffers and IBs that we previously explicitly wrote there. I'm afraid these patches might just paper over bugs elsewhere, which might still bite us under different circumstances. [ml] so do you mean we should use NOP to fulfill the ring buffer instead of 0 ? -----Original Message----- From: Michel Dänzer [mailto:michel@xxxxxxxxxxx] Sent: Tuesday, June 07, 2016 3:34 PM To: Alex Deucher <alexdeucher@xxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; Liu, Monk <Monk.Liu@xxxxxxx> Subject: Re: [PATCH 1/4] drm/amdgpu: clear RB at ring init On 02.06.2016 07:27, Alex Deucher wrote: > From: Monk Liu <Monk.Liu@xxxxxxx> > > This help fix reloading driver hang issue of SDMA ring. > > Signed-off-by: Monk Liu <Monk.Liu@xxxxxxx> > Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> > Reviewed-by: Christian König <christian.koenig@xxxxxxx> > Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c > index 3b02272..a4b3f44 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c > @@ -310,6 +310,9 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring, > } > r = amdgpu_bo_kmap(ring->ring_obj, > (void **)&ring->ring); > + > + memset((void *)ring->ring, 0, ring->ring_size); > + > amdgpu_bo_unreserve(ring->ring_obj); > if (r) { > dev_err(adev->dev, "(%d) ring map failed\n", r); > We should only call memset if amdgpu_bo_kmap succeeded. Same issue in patch 2. There's something else about these two patches I'm a bit worried about: The GPU should only read data from ring buffers and IBs that we previously explicitly wrote there. I'm afraid these patches might just paper over bugs elsewhere, which might still bite us under different circumstances. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
