On Fri, 7 Jul 2017 11:01:16 -0400 Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote: > Hi Wim, > > On 7/7/2017 10:53 AM, Sinan Kaya wrote: > > According to extended tags ECN document, all PCIe receivers are expected > > to support extended tags support. It should be safe to enable extended > > tags on endpoints without checking compatibility. > > > > This assumption seems to be working fine except for the legacy systems. > > The ECN has been written against PCIE spec version 2.0. Therefore, we need > > to exclude all version 1.0 devices from this change as there is HW out > > there that can't handle extended tags. > > > > Note that the default value of Extended Tags Enable bit is implementation > > specific. Therefore, we are clearing the bit by default when incompatible > > HW is found without assuming that value is zero. > > > > Reported-by: Wim ten Have <wim.ten.have@xxxxxxxxxx> > > Link: https://pcisig.com/sites/default/files/specification_documents/ECN_Extended_Tag_Enable_Default_05Sept2008_final.pdf > > Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674 > > Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") > > Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> > > --- > > Can you also give this a spin? I don't have a system with v1 PCIe bridges. > I only tested v2 and later code path. > > I tried to address Jike Song concerns on this version and removed your tested-by > since the code changed. > > Sinan > Sure, -- Wim ten Have | Consulting Member of Technical Staff Oracle Linux and VM Development Engineering ORACLE Nederland BV | Hertogswetering 163-167 | 3543 AS Utrecht/NL
