Messages in this thread | | | Date | Mon, 4 Sep 2023 01:41:38 +0100 | Subject | Re: [PATCH AUTOSEL 5.10 13/22] drm/amdgpu: install stub fence into potential unused fence pointers | From | Eddie Chapman <> |
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On 01/09/2023 07:02, Christian König wrote: > Am 31.08.23 um 20:55 schrieb Chia-I Wu: >> On Thu, Aug 31, 2023 at 7:01 AM Greg KH <gregkh@linuxfoundation.org> >> wrote: >>> On Thu, Aug 31, 2023 at 03:26:28PM +0200, Christian König wrote: >>>> Am 31.08.23 um 12:56 schrieb Greg KH: >>>>> 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@kernel.org> >>>>>>> wrote: >>>>>>>> From: Lang Yu <Lang.Yu@amd.com> >>>>>>>> >>>>>>>> [ 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@amd.com> >>>>>>>> Signed-off-by: Lang Yu <Lang.Yu@amd.com> >>>>>>>> Reviewed-by: Christian König <christian.koenig@amd.com> >>>>>>>> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> >>>>>>>> Signed-off-by: Sasha Levin <sashal@kernel.org> >>>>>>>> --- >>>>>>>> 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. >>>> Could we prevent patches from being backported by adding a Fixes: tag? >>> Yes, that will show exactly where the patch should be backported to. >> This is also AUTOSEL'ed to 5.15. That might need a revert as well, >> depending on when the amdgpu feature landed. > > Both the feature and the bug fix landed in 6.5. > > The bug fix should have never been backported to any older kernel at all > as far as I can see. > > Regards, > Christian.
I can confirm I've also started to get this warning hundreds of times per second having upgraded from 5.15.123 to 5.15.130. There's also a report from someone else of exactly the same on 5.15.128, here: https://gitlab.freedesktop.org/drm/amd/-/issues/2820
Eddie
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