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| author | Bjørn Mork <bjorn@mork.no> | 2018-09-28 15:40:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-02 12:05:30 -0700 |
| commit | 355c74e55e9992126ec5e568a3edb8e280fe040d (patch) | |
| tree | 0d45517642de599088dede57dc0d51144edbc25e /Documentation/ABI | |
| parent | bd0e6c9614b95352eb31d0207df16dc156c527fa (diff) | |
| download | linux-stable-355c74e55e9992126ec5e568a3edb8e280fe040d.tar.gz linux-stable-355c74e55e9992126ec5e568a3edb8e280fe040d.tar.bz2 linux-stable-355c74e55e9992126ec5e568a3edb8e280fe040d.zip | |
usb: export firmware port location in sysfs
The platform firmware "location" data is used to find port peer
relationships. But firmware is an unreliable source, and there are
real world examples of errors leading to missing or wrong peer
relationships. Debugging this is currently hard.
Exporting the location attribute makes it easier to spot mismatches
between the firmware data and the real world.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index c4a70f532ec3..559baa5c418c 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -189,6 +189,16 @@ Description: The file will read "hotplug", "wired" and "not used" if the information is available, and "unknown" otherwise. +What: /sys/bus/usb/devices/.../(hub interface)/portX/location +Date: October 2018 +Contact: Bjørn Mork <bjorn@mork.no> +Description: + Some platforms provide usb port physical location through + firmware. This is used by the kernel to pair up logical ports + mapping to the same physical connector. The attribute exposes the + raw location value as a hex integer. + + What: /sys/bus/usb/devices/.../(hub interface)/portX/quirks Date: May 2018 Contact: Nicolas Boichat <drinkcat@chromium.org> |