On Thu, Aug 31, 2023 at 12:27:27PM +0200, Christian König wrote: > Am 30.08.23 um 20:53 schrieb Chia-I Wu: > > On Sun, Jul 23, 2023 at 6:24 PM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > > From: Lang Yu <Lang.Yu@xxxxxxx> > > > > > > [ Upstream commit 187916e6ed9d0c3b3abc27429f7a5f8c936bd1f0 ] > > > > > > When using cpu to update page tables, vm update fences are unused. > > > Install stub fence into these fence pointers instead of NULL > > > to avoid NULL dereference when calling dma_fence_wait() on them. > > > > > > Suggested-by: Christian König <christian.koenig@xxxxxxx> > > > Signed-off-by: Lang Yu <Lang.Yu@xxxxxxx> > > > Reviewed-by: Christian König <christian.koenig@xxxxxxx> > > > Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> > > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > > --- > > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > We start getting this warning spew on chromeos > > Yeah because the older kernels still kept track of the last VM fence in the > syncobj. > > This patch here should probably not have been back ported. > > Why was that done anyway? The upstream commit doesn't have a CC stable and > this is only a bug fix for a new feature not present on older kernels. It is part of the AUTOSEL process.
