On Thu, Jun 15, 2023 at 03:04:20PM +0800, Kai-Heng Feng wrote: > When a PCIe device is hotplugged to a Thunderbolt port, ASPM is not > enabled for that device. However, when the device is plugged preboot, > ASPM is enabled by default. > > The disparity happens because BIOS doesn't have the ability to program > ASPM on hotplugged devices. > > So enable ASPM by default for external connected PCIe devices so ASPM > settings are consitent between preboot and hotplugged. > > On HP Thunderbolt Dock G4, enable ASPM can also fix BadDLLP error: > pcieport 0000:00:1d.0: AER: Corrected error received: 0000:07:04.0 > pcieport 0000:07:04.0: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Receiver ID) > pcieport 0000:07:04.0: device [8086:0b26] error status/mask=00000080/00002000 > pcieport 0000:07:04.0: [ 7] BadDLLP > > The root cause is still unclear, but quite likely because the I225 on > the dock supports PTM, where ASPM timing is precalculated for the PTM. > Link: https://bugzilla.kernel.org/show_bug.cgi?id=217557 I know you said this isn't clear yet, but I don't see a connection between ASPM being enabled and PTM. If anything, *disabling* ASPM should be safer if there's a timing issue. I assume the ASPM timing you refer to is the LTR snoop/no snoop latency, since that's the only timing difference I see in the lspci output in bugzilla? I don't see any PTM differences there. Bjorn
