diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-usb')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 39 |
1 files changed, 11 insertions, 28 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index a07c0f366f91..294aa864a60a 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -14,34 +14,6 @@ Description: The autosuspend delay for newly-created devices is set to the value of the usbcore.autosuspend module parameter. -What: /sys/bus/usb/devices/.../power/level -Date: March 2007 -KernelVersion: 2.6.21 -Contact: Alan Stern <stern@rowland.harvard.edu> -Description: - Each USB device directory will contain a file named - power/level. This file holds a power-level setting for - the device, either "on" or "auto". - - "on" means that the device is not allowed to autosuspend, - although normal suspends for system sleep will still - be honored. "auto" means the device will autosuspend - and autoresume in the usual manner, according to the - capabilities of its driver. - - During normal use, devices should be left in the "auto" - level. The "on" level is meant for administrative uses. - If you want to suspend a device immediately but leave it - free to wake up in response to I/O requests, you should - write "0" to power/autosuspend. - - Device not capable of proper suspend and resume should be - left in the "on" level. Although the USB spec requires - devices to support suspend/resume, many of them do not. - In fact so many don't that by default, the USB core - initializes all non-hub devices in the "on" level. Some - drivers may change this setting when they are bound. - What: /sys/bus/usb/devices/.../power/persist Date: May 2007 KernelVersion: 2.6.23 @@ -159,3 +131,14 @@ Description: device. This is useful to ensure auto probing won't match the driver to the device. For example: # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id + +What: /sys/bus/usb/device/.../avoid_reset_quirk +Date: December 2009 +Contact: Oliver Neukum <oliver@neukum.org> +Description: + Writing 1 to this file tells the kernel that this + device will morph into another mode when it is reset. + Drivers will not use reset for error handling for + such devices. +Users: + usb_modeswitch |