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From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org,
	Andreas Noever <andreas.noever@gmail.com>,
	Michael Jamet <michael.jamet@intel.com>,
	Yehezkel Bernat <YehezkelShB@gmail.com>,
	Rajmohan Mani <rajmohan.mani@intel.com>,
	Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>,
	Lukas Wunner <lukas@wunner.de>,
	Alan Stern <stern@rowland.harvard.edu>,
	Mario.Limonciello@dell.com,
	Anthony Wong <anthony.wong@canonical.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 08/22] thunderbolt: Add downstream PCIe port mappings for Alpine and Titan Ridge
Date: Tue, 1 Oct 2019 16:27:02 +0300
Message-ID: <20191001132702.GQ2714@lahna.fi.intel.com> (raw)
In-Reply-To: <20191001124054.GC2954373@kroah.com>

On Tue, Oct 01, 2019 at 02:40:54PM +0200, Greg Kroah-Hartman wrote:
> On Tue, Oct 01, 2019 at 02:38:16PM +0300, Mika Westerberg wrote:
> > In order to keep PCIe hierarchies consistent across hotplugs, add
> > hard-coded PCIe downstream port to Thunderbolt port for Alpine Ridge and
> > Titan Ridge as well.
> 
> Oh, that makes me nervous, how could a hard-coded pcie port ever get set
> up incorrectly :)
> 
> How do we "know" that this is correct?  Is there any ACPI guarantees
> that this "always will be so"?  If not, we all know someone will mess
> this up...

For Alpine Ridge and Titan Ridge the PCIe ports are always the same.

Basically what this is about is that you have up to two Thunderbolt
ports (type-C ports). When you plug in Thunderbolt device and PCIe gets
tunneled, the PCIe hierarchy always is always extended from the same
PCIe downstream port.

If we don't do this then the PCIe device may be changing its address
each plug/unplug. Also for older generations (that code is already in
mainline) there are PCIe downstream ports that do not have enough
resources for additional devices.

> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > ---
> >  drivers/thunderbolt/tb.c |  4 +++-
> >  drivers/thunderbolt/tb.h | 25 +++++++++++++++++++++++++
> >  2 files changed, 28 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
> > index dbbe9afb9fb7..704455a4f763 100644
> > --- a/drivers/thunderbolt/tb.c
> > +++ b/drivers/thunderbolt/tb.c
> > @@ -344,10 +344,12 @@ static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
> >  		 * Hard-coded Thunderbolt port to PCIe down port mapping
> >  		 * per controller.
> >  		 */
> > -		if (tb_switch_is_cr(sw))
> > +		if (tb_switch_is_cr(sw) || tb_switch_is_ar(sw))
> >  			index = !phy_port ? 6 : 7;
> >  		else if (tb_switch_is_fr(sw))
> >  			index = !phy_port ? 6 : 8;
> > +		else if (tb_switch_is_tr(sw))
> > +			index = !phy_port ? 8 : 9;
> >  		else
> >  			goto out;
> >  
> > diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
> > index e641dcebd50a..dbab06551eaa 100644
> > --- a/drivers/thunderbolt/tb.h
> > +++ b/drivers/thunderbolt/tb.h
> > @@ -632,6 +632,31 @@ static inline bool tb_switch_is_fr(const struct tb_switch *sw)
> >  	}
> >  }
> >  
> > +static inline bool tb_switch_is_ar(const struct tb_switch *sw)
> 
> "ar"?  Can you spell it out?

You mean call this tb_switch_is_alpine_ridge()? Sure,  I will then do
the same for tb_switch_is_fr() and the existing ones.

> 
> > +{
> > +	switch (sw->config.device_id) {
> > +	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_BRIDGE:
> > +	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
> > +	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
> > +	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
> > +		return true;
> > +	default:
> > +		return false;
> > +	}
> > +}
> > +
> > +static inline bool tb_switch_is_tr(const struct tb_switch *sw)
> 
> Same for "tr" please.

Sure.

  reply index

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-01 11:38 [RFC PATCH 00/22] thunderbolt: Add support for USB4 Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 01/22] thunderbolt: Introduce tb_switch_is_icm() Mika Westerberg
2019-10-01 12:10   ` Greg Kroah-Hartman
2019-10-01 12:46     ` Mika Westerberg
2019-10-01 13:36       ` Mario.Limonciello
2019-10-01 13:48         ` Mika Westerberg
2019-10-01 13:50           ` Mario.Limonciello
2019-10-01 13:52             ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 02/22] thunderbolt: Log switch route string on config read/write timeout Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 03/22] thunderbolt: Log warning if adding switch fails Mika Westerberg
2019-10-01 12:18   ` Greg Kroah-Hartman
2019-10-01 12:48     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 04/22] thunderbolt: Make tb_sw_write() take const parameter Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 05/22] thunderbolt: Add helper macros to iterate over switch ports Mika Westerberg
2019-10-02 14:17   ` Oliver Neukum
2019-10-02 14:28     ` Mika Westerberg
2019-10-06 12:15       ` Lukas Wunner
2019-10-01 11:38 ` [RFC PATCH 06/22] thunderbolt: Add support for lane bonding Mika Westerberg
2019-10-01 12:38   ` Greg Kroah-Hartman
2019-10-01 12:53     ` Mika Westerberg
2019-10-02 14:21       ` Oliver Neukum
2019-10-02 14:30         ` Mika Westerberg
2019-10-03  8:25           ` Oliver Neukum
2019-10-03  8:53             ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 07/22] thunderbolt: Add default linking between ports if not provided by DROM Mika Westerberg
2019-10-01 12:39   ` Greg Kroah-Hartman
2019-10-01 13:14     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 08/22] thunderbolt: Add downstream PCIe port mappings for Alpine and Titan Ridge Mika Westerberg
2019-10-01 12:40   ` Greg Kroah-Hartman
2019-10-01 13:27     ` Mika Westerberg [this message]
2019-10-01 11:38 ` [RFC PATCH 09/22] thunderbolt: Convert basic adapter register names to follow the USB4 spec Mika Westerberg
2019-10-01 12:41   ` Greg Kroah-Hartman
2019-10-01 13:28     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 10/22] thunderbolt: Convert PCIe adapter register names to use USB4 names Mika Westerberg
2019-10-01 12:42   ` Greg Kroah-Hartman
2019-10-01 11:38 ` [RFC PATCH 11/22] thunderbolt: Convert DP adapter register names to follow the USB4 spec Mika Westerberg
2019-10-01 12:42   ` Greg Kroah-Hartman
2019-10-01 11:38 ` [RFC PATCH 12/22] thunderbolt: Add Display Port CM handshake for Titan Ridge devices Mika Westerberg
2019-10-01 12:44   ` Greg Kroah-Hartman
2019-10-01 13:30     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 13/22] thunderbolt: Add Display Port adapter pairing and resource management Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 14/22] thunderbolt: Add bandwidth management for Display Port tunnels Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 15/22] thunderbolt: Make tb_find_port() available to other files Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 16/22] thunderbolt: Call tb_eeprom_get_drom_offset() from tb_eeprom_read_n() Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 17/22] thunderbolt: Add initial support for USB4 Mika Westerberg
2019-10-01 12:47   ` Greg Kroah-Hartman
2019-10-01 13:09     ` Mika Westerberg
2019-10-01 14:53       ` Greg Kroah-Hartman
2019-10-01 14:59         ` Mario.Limonciello
2019-10-01 15:13           ` Mika Westerberg
2019-10-01 15:22           ` Greg KH
2019-10-01 15:32             ` Mika Westerberg
2019-10-01 15:07         ` Mika Westerberg
2019-10-01 15:19           ` Greg Kroah-Hartman
2019-10-01 15:26             ` Mika Westerberg
2019-10-01 16:27           ` Oliver Neukum
2019-10-02  8:30             ` Mika Westerberg
2019-10-02  8:39               ` Greg Kroah-Hartman
2019-10-02  8:49                 ` Mika Westerberg
2019-10-01 17:05   ` Mario.Limonciello
2019-10-01 18:14     ` Mario.Limonciello
2019-10-02  8:39       ` Mika Westerberg
2019-10-02 15:09         ` Mario.Limonciello
2019-10-02 15:36           ` Yehezkel Bernat
2019-10-02 16:00             ` Mario.Limonciello
2019-10-03  8:00               ` Mika Westerberg
2019-10-03 14:41                 ` Mario.Limonciello
2019-10-04  7:54                   ` Mika Westerberg
2019-10-04  8:07                     ` Yehezkel Bernat
2019-10-04  8:19                       ` Mika Westerberg
2019-10-04 11:19                         ` Yehezkel Bernat
2019-10-04 14:05                           ` Mario.Limonciello
2019-10-04 14:19                             ` Mario.Limonciello
2019-10-04 14:21                             ` Mika Westerberg
     [not found]                               ` <1570201357.2.0@kellner.me>
2019-10-04 15:16                                 ` Mika Westerberg
2019-10-04 15:22                                   ` Christian Kellner
2019-10-02  8:34     ` Mika Westerberg
2019-10-02 15:04       ` Mario.Limonciello
2019-10-01 11:38 ` [RFC PATCH 18/22] thunderbolt: Make tb_switch_find_cap() available to other files Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 19/22] thunderbolt: Add support for Time Management Unit Mika Westerberg
2019-10-02 16:52   ` Mani, Rajmohan
2019-10-03  8:01     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 20/22] thunderbolt: Add support for USB tunnels Mika Westerberg
2019-10-03  8:42   ` Oliver Neukum
2019-10-03  8:52     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 21/22] thunderbolt: Update documentation with the USB4 information Mika Westerberg
2019-10-01 14:17   ` Mario.Limonciello
2019-10-01 14:21     ` Mika Westerberg
2019-10-01 11:38 ` [RFC PATCH 22/22] thunderbolt: Do not start firmware unless asked by the user Mika Westerberg
2019-10-01 14:43   ` Mario.Limonciello
2019-10-01 14:58     ` Mika Westerberg
2019-10-01 16:53       ` Mario.Limonciello
2019-10-02  8:48         ` Mika Westerberg
2019-10-01 12:49 ` [RFC PATCH 00/22] thunderbolt: Add support for USB4 Greg Kroah-Hartman
2019-10-01 13:42   ` Mika Westerberg

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