Re: [PATCH v2] pci: quirks: Disable native PCIe hotplug on MSI Claw A8 root bridge

> The MSI Claw A8 (MS-1T8K) hard-locks on resume from s2idle whenever an
> SD/MMC card is present in the onboard Realtek RTS525A card reader
> (10ec:525a), which sits behind root port 0000:00:02.2. The reader's
> PCIe endpoint is fixed/soldered and not user-hotpluggable.
> 
> Firmware advertises this root port as PCIe hotplug-capable, and _OSC
> grants the OS native hotplug control. When native hotplug is OS-owned,
> resuming from s2idle races the port's hotplug/PME resume handling
> against the RTS525A's own resume sequence when a card is present,
> hard-locking the system.
> 
> Two kernel command line parameters were confirmed to prevent the hang:
> pcie_aspm=off and pcie_ports=compat. Both stop the OS from running
> its own hotplug/PME resume path against this port. The former does
> so by dropping _OSC negotiation during boot, skipping the path that
> [ ... ]
> 
> SD card insertion is handled entirely by rtsx_pci's own card-detect logic,
> so is unaffected by this quirk.
> 
> Signed-off-by: Derek J. Clark <[email protected]>

Sashiko has reviewed this patch and found no issues. It looks great!

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