Re: [PATCH 4/5] thunderbolt: Correlate PCI devices with Thunderbolt ports

From: Mika Westerberg
Date: Thu Sep 13 2018 - 05:58:00 EST


On Thu, Sep 13, 2018 at 12:43:03PM +0300, Yehezkel Bernat wrote:
> On Mon, Sep 10, 2018 at 12:45 PM Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> >
> > Hi Lukas,
> >
> > On Sun, Sep 09, 2018 at 11:42:01PM +0200, Lukas Wunner wrote:
> > > Ideas what we can do with correlation:
> > >
> > > * Represent the relationship between PCI devices and Thunderbolt ports
> > > with symlinks in sysfs.
> >
> > I wonder is that really useful? I don't think we should be adding sysfs
> > entries without any real reason why it would be needed and who would be
> > using them.
>
> I think Lukas mentioned where it can be useful, even if it isn't used right now.
> We also know this can be useful for some QoS configurations (even if we didn't
> found it useful enough for now).

I have no doubts that is not useful :) The issue is that currently it
does not do anything except adds this functionality to the driver but
nobody uses it. Like in the other parts of the kernel, let's merge this
at the same time when there is a legitimate user for the feature.