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charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, 7 Sep 2020 at 08:00, Christoph Hellwig wrote: > > On Thu, Sep 03, 2020 at 09:18:37PM +0100, Tom Murphy wrote: > > Disable combining sg segments in the dma-iommu api. > > Combining the sg segments exposes a bug in the intel i915 driver which > > causes visual artifacts and the screen to freeze. This is most likely > > because of how the i915 handles the returned list. It probably doesn't > > respect the returned value specifying the number of elements in the list > > and instead depends on the previous behaviour of the intel iommu driver > > which would return the same number of elements in the output list as in > > the input list. > > So what is the state of addressing this properly in i915? IF we can't I think this is the latest on addressing this issue: https://patchwork.kernel.org/cover/11306999/ tl;dr: some people seem to be looking at it but I'm not sure if it's being actively worked on > get it done ASAP I wonder if we need a runtime quirk to disable > merging instead of blocking this conversion.. Yeah we talked about passing an attr to map_sg to disable merging at the following microconfernce: https://linuxplumbersconf.org/event/7/contributions/846/ As far as I can remember everyone seemed happy with that solution. I won't be working on this though as I don't have any more time to dedicate to this. It seems Lu Baolu will take over this. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu