On Mon, Jul 21, 2025 at 09:17:55PM +0800, Shuai Xue wrote:

2025/7/19 15:11, Lukas Wunner :

quoted

PCI links can be tunneled over Thunderbolt, in this case the
link speed is fixed to 2.5 GT/s (USB4 v1.0 sec 11.2.1), but
in reality is governed by the speed of the Thunderbolt fabric
(which can even be asymmetric).  Do we want to report the
virtual 2.5 GT/s in this case or the actual Thunderbolt speed?
Or do we want a separate trace event for Thunderbolt?

I'm not a user of Thunderbolt, which way do you prefer?

Keep reporting the virtual 2.5 GT/s in the PCI tracepoint and
maybe add a separate tracepoint later in the thunderbolt driver
to report the Thunderbolt speed.

Thanks,

Lukas