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Date:   Fri, 4 Feb 2022 16:01:32 -0700
From:   dann frazier <dann.frazier@canonical.com>
To:     Rob Herring <robh@kernel.org>
Cc:     Toan Le <toan@os.amperecomputing.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>,
        =?iso-8859-1?Q?St=E9phane?= Graber <stgraber@ubuntu.com>,
        stable@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: xgene: Fix IB window setup
Message-ID: <Yf2wTLjmcRj+AbDv@xps13.dannf>
References: <20211129173637.303201-1-robh@kernel.org>
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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 St?phane'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 St?phane'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

   -dann