Re: [PATCH] PCI: Add quirk for Cavium Thunder-X2 PCIe erratum #173

[Lukas Wunner]

On Wed, Feb 21, 2018 at 02:58:13PM +0530, George Cherian wrote:
> I will explain the setup used
> To the Cavium ThunderX RC the following PLX device is connected.
> PLX Technology, Inc. PEX 8747 48-Lane, 5-Port PCI Express Gen 3 (8.0 GT/s)
> Switch
> There is no device connected downstream to the PLX switch.
> 
> AFAIU the pcie_port driver probes PLX and enters autosuspend after 100ms
> since pci_bridge_d3_possible() returns true.
> 
> And later pci_sysfs_init() ends up doing a config access of PLX which fails
> with a "synchronous external abort"

Then you're missing a pci_config_pm_runtime_get() in pci_sysfs_init() or
further down in the call stack, rather than a quirk which just papers
over the issue.

Thanks,

Lukas