[PATCH] PCI: xgene: Fix IB window setup

[dann frazier]

On Sat, Feb 5, 2022 at 9:05 AM Rob Herring <robh at kernel.org> wrote:
>
> On Fri, Feb 4, 2022 at 5:01 PM dann frazier <dann.frazier at canonical.com> wrote:
> >
> > On Mon, Nov 29, 2021 at 11:36:37AM -0600, Rob Herring wrote:
> > > Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
> > > broke PCI support on XGene. The cause is the IB resources are now sorted
> > > in address order instead of being in DT dma-ranges order. The result is
> > > which inbound registers are used for each region are swapped. I don't
> > > know the details about this h/w, but it appears that IB region 0
> > > registers can't handle a size greater than 4GB. In any case, limiting
> > > the size for region 0 is enough to get back to the original assignment
> > > of dma-ranges to regions.
> >
> > hey Rob!
> >
> > I've been seeing a panic on HP Moonshoot m400 cartridges (X-Gene1) -
> > only during network installs - that I also bisected down to commit
> > 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup"). I was
> > hoping that this patch that fixed the issue on Stéphane's X-Gene2
> > system would also fix my issue, but no luck. In fact, it seems to just
> > makes it fail differently. Reverting both patches is required to get a
> > v5.17-rc kernel to boot.
> >
> > I've collected the following logs - let me know if anything else would
> > be useful.
> >
> > 1) v5.17-rc2+ (unmodified):
> >    http://dannf.org/bugs/m400-no-reverts.log
> >    Note that the mlx4 driver fails initialization.
> >
> > 2) v5.17-rc2+, w/o the commit that fixed Stéphane's system:
> >    http://dannf.org/bugs/m400-xgene2-fix-reverted.log
> >    Note the mlx4 MSI-X timeout, and later panic.
> >
> > 3) v5.17-rc2+, w/ both commits reverted (works)
> >    http://dannf.org/bugs/m400-both-reverted.log
>
> The ranges and dma-ranges addresses don't appear to match up with any
> upstream dts files. Can you send me the DT?

Sure: http://dannf.org/bugs/fdt

 -dann

> Otherwise, we're going to need some debugging added to
> xgene_pcie_setup_ib_reg() to see if the register setup changed. I can
> come up with something next week.
>
> Rob