[BUG] PCIe on Armada 388 broken since 5.9

[Russell King - ARM Linux admin]

On Thu, Oct 22, 2020 at 10:18:21PM +0100, Russell King - ARM Linux admin wrote:
> Hi,
> 
> It appears that PCIe on Armada 388 has been broken in 5.9. Here are
> the boot messages:
> 
> mvebu-pcie soc:pcie: host bridge /soc/pcie ranges:
> mvebu-pcie soc:pcie:      MEM 0x00f1080000..0x00f1081fff -> 0x0000080000
> mvebu-pcie soc:pcie:      MEM 0x00f1040000..0x00f1041fff -> 0x0000040000
> mvebu-pcie soc:pcie:      MEM 0x00f1044000..0x00f1045fff -> 0x0000044000
> mvebu-pcie soc:pcie:      MEM 0x00f1048000..0x00f1049fff -> 0x0000048000
> mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0100000000
> mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0100000000
> mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0200000000
> mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0200000000
> mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0300000000
> mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0300000000
> mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0400000000
> mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0400000000
> mvebu-pcie soc:pcie: resource collision: [mem 0xf1080000-0xf1081fff] conflicts with pcie [mem 0xf1080000-0xf1081fff]
> mvebu-pcie: probe of soc:pcie failed with error -16
> 
> This results in PCIe being entirely non-functional. At a guess, I'd
> say it's due to:
> 
> commit c322fa0b3fa948010a278794e60c45ec860e4a1e
> Author: Rob Herring <robh at kernel.org>
> Date:   Fri May 22 17:48:19 2020 -0600
> 
>     PCI: mvebu: Use struct pci_host_bridge.windows list directly
> 
>     There's no need to create a temporary resource list and then splice it to
>     struct pci_host_bridge.windows list. Just use pci_host_bridge.windows
>     directly. The necessary clean-up is already handled by the PCI core.
> 
>     Link: https://lore.kernel.org/r/20200522234832.954484-3-robh@kernel.org
>     Signed-off-by: Rob Herring <robh at kernel.org>
>     Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
>     Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
>     Cc: Jason Cooper <jason at lakedaemon.net>

Confirmed. Reverting this commit results in functioning PCIe.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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