Re: [PATCH 1/1] PCI: Cleanup link activation wait logic

From: Maciej W. Rozycki
Date: Mon Feb 26 2024 - 07:57:27 EST


On Fri, 16 Feb 2024, Ilpo Järvinen wrote:

> > > Yet another thing in this quirk code I don't like is how it can leaves the
> > > target speed to 2.5GT/s when the quirk fails to get the link working
> > > (which actually does happen in the disconnection cases because DLLLA won't
> > > be set so the target speed will not be restored).
> >
> > I chose to leave the target speed at the most recent setting, because the
> > link doesn't work in that case anyway, so I concluded it doesn't matter,
> > but reduces messing with the device; technically you should retrain again
> > afterwards. I'm not opposed to changing this if you have a use case.
>
> It remains suboptimally set in a case where something is plugged again
> into that port, for Thunderbolt it doesn't matter as the PCIe speed picked
> is quite bogus anyway, but disconnect then plug something again is not
> limited to Thunderbolt.

Sure, my understanding has been all PCIe option devices are supposed to
be hot-pluggable, at least these in the regular form factor (which is why
PCIe edge connector contacts have varying lengths, unlike conventional
PCI).

Maciej