Re: [PATCH v2 1/2] iommu: Quirked PCIe bridge test and search function

[Alex Williamson <alex.williamson@redhat.com>]

On Tue, 2013-05-28 at 12:56 -0700, Stephen Hemminger wrote:
> On Tue, 28 May 2013 13:53:10 -0600
> Alex Williamson <alex.williamson@redhat.com> wrote:
> 
> > On Tue, 2013-05-28 at 12:38 -0700, Stephen Hemminger wrote:
> > > On Tue, 28 May 2013 12:40:20 -0600
> > > Alex Williamson <alex.williamson@redhat.com> wrote:
> > > 
> > > > Some PCIe-to-PCI bridges are not fully compliant with the PCIe spec
> > > > and do not include a PCIe capability.  pci_is_pcie() is not useful on
> > > > these devices, making it difficult to determine where we transition
> > > > from a legacy PCI bus to a PCIe link.  PCI-core doesn't want a quirked
> > > > bridge test for fear of confusion that a PCIe capability would be
> > > > expected, so implement it in IOMMU code.
> > > > 
> > > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> > > 
> > > This won't work for me because I run without IOMMU.
> > > The overhead of IOMMU setup per-packet significantly impacts network performance.
> > 
> > You were one of the reporters of this issue:
> > 
> > http://www.spinics.net/lists/linux-pci/msg19579.html
> > 
> > Does this not work for you or are you saying this is not relevant to you
> > because you no longer attempt to enable the IOMMU?  Thanks,
> > 
> 
> For most usage, I gave up on using IOMMU/SR-IOV.

Ok, let's call that a "don't care" rather than "won't work" for the
purposes of these patches.  I'll take you off the CC if there's another
version.  Thanks,

Alex