From: Lukas Wunner <lukas@wunner.de>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-kernel@vger.kernel.org,
Michael Jamet <michael.jamet@intel.com>,
Yehezkel Bernat <YehezkelShB@gmail.com>,
Andreas Noever <andreas.noever@gmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: [PATCH v2 14/28] thunderbolt: Extend tunnel creation to more than 2 adjacent switches
Date: Tue, 12 Feb 2019 13:54:17 +0100 [thread overview]
Message-ID: <20190212125417.4an7efllnf7pqw2v@wunner.de> (raw)
In-Reply-To: <20190211084558.GU7875@lahna.fi.intel.com>
On Mon, Feb 11, 2019 at 10:45:58AM +0200, Mika Westerberg wrote:
> On Sun, Feb 10, 2019 at 04:33:28PM +0100, Lukas Wunner wrote:
> > at the bottom of this page there's
> > a figure showing a PCI tunnel between non-adjacent switches (blue line):
> >
> > https://developer.apple.com/library/archive/documentation/HardwareDrivers/Conceptual/ThunderboltDevGuide/Basics/Basics.html
> >
> Are you sure Apple actually uses setup like that? I think I have never
> seen such configuration happening on any of the devices I have.
Sorry, I don't know if they actually use that.
> I can update the changelog to mention that if you think it is useful.
> Something like below maybe?
>
> PCIe actually does not need this as it is typically a daisy chain
> between two adjacent switches but this way we do not need to hard-code
> creation of the tunnel.
LGTM, thanks.
> > > + i = 0;
> > > + tb_for_each_port(in_port, src, dst)
> > > + i++;
> >
> > This looks more complicated than necessary. Isn't the path length
> > always the length of the route string from in_port switch to out_port
> > switch, plus 2 for the adapter on each end? Or do paths without
> > adapters exist?
>
> Yes, I think you are right.
Simply subtracting the depths of the start and end port's switch also yields
the path length. Of course this assumes that tunnels aren't established
between non-adjacent switches, but your algorithm doesn't do that.
Thanks,
Lukas
next prev parent reply other threads:[~2019-02-12 12:54 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 13:17 [PATCH v2 00/28] thunderbolt: Software connection manager improvements Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 01/28] net: thunderbolt: Unregister ThunderboltIP protocol handler when suspending Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 02/28] thunderbolt: Do not allocate switch if depth is greater than 6 Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 03/28] thunderbolt: Enable TMU access when accessing port space on legacy devices Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 04/28] thunderbolt: Add dummy read after port capability list walk on Light Ridge Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 05/28] thunderbolt: Move LC specific functionality into a separate file Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 06/28] thunderbolt: Configure lanes when switch is initialized Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 07/28] thunderbolt: Set sleep bit when suspending switch Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 08/28] thunderbolt: Properly disable path Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 09/28] thunderbolt: Cache adapter specific capability offset into struct port Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 10/28] thunderbolt: Rename tunnel_pci to tunnel Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 11/28] thunderbolt: Generalize tunnel creation functionality Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 12/28] thunderbolt: Add functions for allocating and releasing hop IDs Mika Westerberg
2019-02-10 12:13 ` Lukas Wunner
2019-02-11 8:30 ` Mika Westerberg
2019-02-12 12:43 ` Lukas Wunner
2019-02-12 12:51 ` Mika Westerberg
2019-02-12 12:59 ` Lukas Wunner
2019-02-12 13:02 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 13/28] thunderbolt: Add helper function to iterate from one port to another Mika Westerberg
2019-02-07 14:33 ` Andy Shevchenko
2019-02-11 6:16 ` Lukas Wunner
2019-02-11 9:54 ` Mika Westerberg
2019-02-12 13:55 ` Lukas Wunner
2019-02-12 19:03 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 14/28] thunderbolt: Extend tunnel creation to more than 2 adjacent switches Mika Westerberg
2019-02-10 15:33 ` Lukas Wunner
2019-02-11 8:45 ` Mika Westerberg
2019-02-12 12:54 ` Lukas Wunner [this message]
2019-02-06 13:17 ` [PATCH v2 15/28] thunderbolt: Deactivate all paths before restarting them Mika Westerberg
2019-02-11 6:35 ` Lukas Wunner
2019-02-11 8:52 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 16/28] thunderbolt: Discover preboot PCIe paths the boot firmware established Mika Westerberg
2019-02-12 17:49 ` Lukas Wunner
2019-02-12 18:34 ` Mika Westerberg
2019-02-12 19:42 ` Lukas Wunner
2019-02-13 8:30 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 17/28] thunderbolt: Add support for full PCIe daisy chains Mika Westerberg
2019-03-24 11:31 ` Lukas Wunner
2019-03-25 9:57 ` Mika Westerberg
2019-03-25 11:16 ` Lukas Wunner
2019-03-25 11:22 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 18/28] thunderbolt: Scan only valid NULL adapter ports in hotplug Mika Westerberg
2019-02-12 14:04 ` Lukas Wunner
2019-02-12 18:46 ` Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 19/28] thunderbolt: Generalize port finding routines to support all port types Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 20/28] thunderbolt: Rework NFC credits handling Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 21/28] thunderbolt: Add support for Display Port tunnels Mika Westerberg
2019-02-07 14:28 ` Andy Shevchenko
2019-02-06 13:17 ` [PATCH v2 22/28] thunderbolt: Run tb_xdp_handle_request() in system workqueue Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 23/28] thunderbolt: Add XDomain UUID exchange support Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 24/28] thunderbolt: Add support for DMA tunnels Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 25/28] thunderbolt: Make tb_switch_alloc() return ERR_PTR() Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 26/28] thunderbolt: Add support for XDomain connections Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 27/28] thunderbolt: Make rest of the logging to happen at debug level Mika Westerberg
2019-02-06 13:17 ` [PATCH v2 28/28] thunderbolt: Start firmware on Titan Ridge Apple systems Mika Westerberg
2019-02-07 14:22 ` [PATCH v2 00/28] thunderbolt: Software connection manager improvements Andy Shevchenko
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