Re: [PATCH] PCI/ASPM: Enable L0s/L1 for removable devices when BIOS didn't configure ASPM

[Bjorn Helgaas]

On Mon, May 04, 2026 at 05:52:46PM -0500, Mario Limonciello wrote:
> When comparing lspci output between Windows and Linux for hotplugged
> Thunderbolt 5 eGPU devices, Windows enables ASPM L1 but Linux doesn't:
> 
>   Windows: LnkCtl: ASPM L1 Enabled
>   Linux:   LnkCtl: ASPM Disabled
> 
> This difference in ASPM configuration can cause behavioral differences
> between the two operating systems for the same hardware.

A tangent, not a comment on the patch itself, but what sort of
behavioral differences are these?  If ASPM is working correctly, the
only differences *should* be in power consumption and performance.