Re: [RFC PATCH 21/22] thunderbolt: Update documentation with the USB4 information

[Mika Westerberg]

On Tue, Oct 01, 2019 at 02:17:01PM +0000, Mario.Limonciello@xxxxxxxx wrote:
> 
> 
> > -----Original Message-----
> > From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> > Sent: Tuesday, October 1, 2019 6:38 AM
> > To: linux-usb@xxxxxxxxxxxxxxx
> > Cc: Andreas Noever; Michael Jamet; Mika Westerberg; Yehezkel Bernat; Rajmohan
> > Mani; Nicholas Johnson; Lukas Wunner; Greg Kroah-Hartman; Alan Stern;
> > Limonciello, Mario; Anthony Wong; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: [RFC PATCH 21/22] thunderbolt: Update documentation with the USB4
> > information
> > 
> > 
> > [EXTERNAL EMAIL]
> > 
> > Update user's and administrator's guide to mention USB4, how it relates
> > to Thunderbolt (it is public spec of Thunderbolt 3) and and how it is
> > supported in Linux.
> > 
> > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> > ---
> >  Documentation/admin-guide/thunderbolt.rst | 27 ++++++++++++++++++-----
> >  1 file changed, 22 insertions(+), 5 deletions(-)
> > 
> > diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-
> > guide/thunderbolt.rst
> > index 898ad78f3cc7..4cbed319133d 100644
> > --- a/Documentation/admin-guide/thunderbolt.rst
> > +++ b/Documentation/admin-guide/thunderbolt.rst
> > @@ -1,6 +1,25 @@
> > -=============
> > - Thunderbolt
> > -=============
> > +======================
> > + Thunderbolt and USB4
> > +======================
> > +USB4 is the public spec of Thunderbolt 3 with some differences at the
> > +register level among other things. There are two different
> > +implementations available: firmware connection manager and software
> > +connection manager. Typically PCs come with a firmware connection
> > +manager for Thunderbolt 3 and early USB4 capable systems. Apple systems
> > +on the other hand use software connection manager and the future USB4
> > +compliant PCs follow the suit.
> 
> Future isn't going to age very well.  Perhaps refer instead to "later" USB4 compliant
> PCs.

Yup.

> Also, we should be seeing this stuff pop-up outside of PCs.  So maybe better
> to just call out "devices".

Indeed, I'll update this accordingly.