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authorNicolas Boichat2018-05-28 14:32:19 +0800
committerGreg Kroah-Hartman2018-05-31 12:48:17 +0200
commitaa071a92bbf09d993ff0dbf3b1f2b53ac93ad654 (patch)
treea6c57deabc0ca7ac0eb080aa3a0d061db8517945 /Documentation
parent25244227158e1502062041365a439a54cb8fe673 (diff)
usb: hub: Per-port setting to reduce TRSTRCY to 10 ms
Currently, the USB hub core waits for 50 ms after enumerating the device. This was added to help "some high speed devices" to enumerate (b789696af8 "[PATCH] USB: relax usbcore reset timings"). On some devices, the time-to-active is important, so we provide a per-port option to reduce the time to what the USB specification requires: 10 ms. Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-usb4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index a31a66d62cbb..08d456e07b53 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -206,6 +206,10 @@ Description:
using /sys/module/usbcore/parameters/old_scheme_first, but
it is often not desirable as the new scheme was introduced to
increase compatibility with more devices.
+ - Bit 1 reduces TRSTRCY to the 10 ms that are required by the
+ USB 2.0 specification, instead of the 50 ms that are normally
+ used to help make enumeration work better on some high speed
+ devices.
What: /sys/bus/usb/devices/.../(hub interface)/portX/over_current_count
Date: February 2018