[PATCH] PCI: xgene: Fix IB window setup

[Rob Herring]

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?

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