On Tue, Apr 10, 2018 at 04:18:01PM -0400, Sinan Kaya wrote: > On 4/10/2018 3:50 PM, Bjorn Helgaas wrote: > > On Tue, Apr 10, 2018 at 02:41:44PM -0500, Bjorn Helgaas wrote: > >> On Wed, Apr 04, 2018 at 06:50:09PM -0400, Sinan Kaya wrote: > >>> Per PCIe r3.1, sec 126.96.36.199 and 7.8.4, a Requester may not use 8-bit Tags > >>> unless its Extended Tag Field Enable is set, but all Receivers/Completers > >>> must handle 8-bit Tags correctly regardless of their Extended Tag Field > >>> Enable. > >>> > >>> Some devices do not handle 8-bit Tags as Completers, so add a quirk for > >>> them. If we find such a device, we disable Extended Tags for the entire > >>> hierarchy to make peer-to-peer DMA possible. > >>> > >>> The Broadcom HT1100/HT2000/HT2100 seems to have issues with handling 8-bit > >>> tags. Mark it as broken. > >>> > >>> Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") > >>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196197 > >>> Signed-off-by: Sinan Kaya <ok...@codeaurora.org> > >> Applied to pci/enumeration for v4.18, thanks! > > Actually, this is a really annoying issue and I think the fix is > > appropriate for v4.17, so I moved it to my for-linus branch. > > > > I agree. It causes boot issues on some AMD Opteron machines. It should > probably be back-ported too.
We started enabling extended tags with 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported"), which appeared in v4.11. So I added these stable tags: CC: sta...@vger.kernel.org # v4.11: 62ce94a7a5a5 PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken CC: sta...@vger.kernel.org # v4.11 I'm not sure I'm using the stable request correctly, but my intent is: - 62ce94a7a5a5 appeared in v4.14, so cherry-pick 62ce94a7a5a5 to v4.11 through v4.13 - cherry-pick *this* patch on top of 62ce94a7a5a5 to v4.11 and later