On 2021-03-29 20:04 +0200, Christian König wrote: > Am 29.03.21 um 19:53 schrieb Xℹ Ruoyao: > > If the initial value of `num_entires` (calculated at line 1654) is not > > an integral multiple of `AMDGPU_GPU_PAGES_IN_CPU_PAGE`, in line 1681 a > > value greater than the initial value will be assigned to it. That causes > > `start > last + 1` after line 1708. Then in the next iteration an > > underflow happens at line 1654. It causes message > > > > *ERROR* Couldn't update BO_VA (-12) > > > > printed in kernel log, and GPU hanging. > > > > Fortify the criteria of the loop to fix this issue. > > NAK the value of num_entries must always be a multiple of > AMDGPU_GPU_PAGES_IN_CPU_PAGE or otherwise we corrupt the page tables. > > How do you trigger that?
Simply run "OpenGL area" from gtk3-demo (which just renders a triangle with GL) under Xorg, on MIPS64. See the BugLink. > Christian. > > > > > BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1549 > > Fixes: a39f2a8d7066 ("drm/amdgpu: nuke amdgpu_vm_bo_split_mapping v2") > > Reported-by: Xi Ruoyao <xry...@mengyan1223.wang> > > Reported-by: Dan Horák <d...@danny.cz> > > Cc: sta...@vger.kernel.org > > Signed-off-by: Xi Ruoyao <xry...@mengyan1223.wang> > > --- > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c > > index ad91c0c3c423..cee0cc9c8085 100644 > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c > > @@ -1707,7 +1707,7 @@ static int amdgpu_vm_bo_update_mapping(struct > > amdgpu_device *adev, > > } > > start = tmp; > > > > - } while (unlikely(start != last + 1)); > > + } while (unlikely(start < last + 1)); > > > > r = vm->update_funcs->commit(¶ms, fence); > > > > > > base-commit: a5e13c6df0e41702d2b2c77c8ad41677ebb065b3 > -- Xi Ruoyao <xry...@mengyan1223.wang> School of Aerospace Science and Technology, Xidian University
