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| author | Kranthi Kuntala <kranthi.kuntala@intel.com> | 2020-03-05 17:39:58 +0300 |
|---|---|---|
| committer | Mika Westerberg <mika.westerberg@linux.intel.com> | 2020-06-22 19:58:32 +0300 |
| commit | dacb12877d9222e0281b8391e3361fd4c7a7435a (patch) | |
| tree | c9cf01118dd0b04124d25bdb39a721ca6bcc03fc /Documentation/admin-guide/thunderbolt.rst | |
| parent | 02d12855f51651cc9cf8e59e6cbb24a5d9e0a054 (diff) | |
| download | linux-dacb12877d9222e0281b8391e3361fd4c7a7435a.tar.xz | |
thunderbolt: Add support for on-board retimers
USB4 spec specifies standard access to retimers (both on-board and
cable) through USB4 port sideband access. This makes it possible to
upgrade their firmware in the same way than we already do with the
routers.
This enumerates on-board retimers under each USB4 port when the link
comes up and adds them to the bus under the router the retimer belongs
to. Retimers are exposed in sysfs with name like <device>:<port>.<index>
where device is the router the retimer belongs to, port is the USB4 port
the retimer is connected to and index is the retimer index under that
port (starting from 1). This applies to the upstream USB4 port as well
so if there is on-board retimer between the port and the router it is
also added accordingly.
At this time we do not add cable retimers but there is no techincal
restriction to do so in the future if needed. It is not clear whether it
makes sense to upgrade their firmwares and at least Thunderbolt 3 cables
it has not been done outside of lab environments.
The sysfs interface is made to follow the router NVM upgrade to make it
easy to extend the existing userspace (fwupd) to handle these as well.
Signed-off-by: Kranthi Kuntala <kranthi.kuntala@intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Diffstat (limited to 'Documentation/admin-guide/thunderbolt.rst')
| -rw-r--r-- | Documentation/admin-guide/thunderbolt.rst | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 10c4f0ce2ad0..613cb24c76c7 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -173,8 +173,8 @@ following ``udev`` rule:: ACTION=="add", SUBSYSTEM=="thunderbolt", ATTRS{iommu_dma_protection}=="1", ATTR{authorized}=="0", ATTR{authorized}="1" -Upgrading NVM on Thunderbolt device or host -------------------------------------------- +Upgrading NVM on Thunderbolt device, host or retimer +---------------------------------------------------- Since most of the functionality is handled in firmware running on a host controller or a device, it is important that the firmware can be upgraded to the latest where possible bugs in it have been fixed. @@ -185,9 +185,10 @@ for some machines: `Thunderbolt Updates <https://thunderbolttechnology.net/updates>`_ -Before you upgrade firmware on a device or host, please make sure it is a -suitable upgrade. Failing to do that may render the device (or host) in a -state where it cannot be used properly anymore without special tools! +Before you upgrade firmware on a device, host or retimer, please make +sure it is a suitable upgrade. Failing to do that may render the device +in a state where it cannot be used properly anymore without special +tools! Host NVM upgrade on Apple Macs is not supported. |