Groups > linux.kernel > #1652059

Re: [PATCH v2 09/27] thunderbolt: Convert switch to a device

From	Mika Westerberg <mika.westerberg@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 09/27] thunderbolt: Convert switch to a device
Date	2017-05-28 10:50 +0200
Message-ID	<tM23D-7ZF-3@gated-at.bofh.it> (permalink)
References	<tLq81-87A-5@gated-at.bofh.it> <tLq82-87A-19@gated-at.bofh.it> <tLM8x-5Sc-7@gated-at.bofh.it>
Organization	Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

Show all headers | View raw

On Sat, May 27, 2017 at 06:45:24PM +0300, Andy Shevchenko wrote:
> On Fri, May 26, 2017 at 7:09 PM, Mika Westerberg
> <mika.westerberg@linux.intel.com> wrote:
> > Thunderbolt domain consists of switches that are connected to each
> > other, forming a bus. This will convert each switch into a real Linux
> > device structure and adds them to the domain. The advantage here is
> > that we get all the goodies from the driver core, like reference
> > counting and sysfs hierarchy for free.
> >
> > Also expose device identification information to the userspace via new
> > sysfs attributes.
> >
> > In order to support internal connection manager (ICM) we separate switch
> > configuration into its own function (tb_switch_configure()) which is
> > only called by the existing native connection manager implementation
> > used on Macs.
> 
> > +       /*
> > +        * The newer controllers include fused UUID as part of link
> > +        * controller specific registers
> > +        */
> > +       cap = tb_switch_find_vsec_cap(sw, TB_VSEC_CAP_LINK_CONTROLLER);
> > +       if (cap > 0) {
> > +               tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
> > +       } else {
> > +               /*
> > +                * By default the UUID will be based on UID where upper two
> > +                * dwords are filled with ones.
> > +                */
> > +               uuid[0] = sw->uid & 0xffffffff;
> > +               uuid[1] = (sw->uid >> 32) & 0xffffffff;
> > +               uuid[2] = 0xffffffff;
> > +               uuid[3] = 0xffffffff;
> > +       }
> 
> It might make sense to add some comment as we discussed earlier
> (privately) about (non-)compatibiliness with UUID by spec and why 0xff
> are used.

OK, I'll update the comment here and also reword the attribute
description in sysfs-bus-thunderbolt.

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v2 09/27] thunderbolt: Convert switch to a device Mika Westerberg <mika.westerberg@linux.intel.com> - 2017-05-26 18:20 +0200
  Re: [PATCH v2 09/27] thunderbolt: Convert switch to a device Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-05-27 17:50 +0200
    Re: [PATCH v2 09/27] thunderbolt: Convert switch to a device Mika Westerberg <mika.westerberg@linux.intel.com> - 2017-05-28 10:50 +0200

csiph-web