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The sysfs power/level interface is still implemented and documented despite the removal notice stating it would be removed after 2010. Remove the outdated removal timeline while keeping the deprecation notice and recommendation to use power/control instead. Signed-off-by: Sardaruddin Syed <ssardaruddin2002@gmail.com> Link: https://patch.msgid.link/20260530233410.1718-1-ssardaruddin2002@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
32 lines
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
What: /sys/bus/usb/devices/.../power/level
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Date: March 2007
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KernelVersion: 2.6.21
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Contact: Alan Stern <stern@rowland.harvard.edu>
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Description:
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Each USB device directory will contain a file named
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power/level. This file holds a power-level setting for
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the device, either "on" or "auto".
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"on" means that the device is not allowed to autosuspend,
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although normal suspends for system sleep will still
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be honored. "auto" means the device will autosuspend
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and autoresume in the usual manner, according to the
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capabilities of its driver.
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During normal use, devices should be left in the "auto"
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level. The "on" level is meant for administrative uses.
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If you want to suspend a device immediately but leave it
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free to wake up in response to I/O requests, you should
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write "0" to power/autosuspend.
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Device not capable of proper suspend and resume should be
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left in the "on" level. Although the USB spec requires
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devices to support suspend/resume, many of them do not.
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In fact so many don't that by default, the USB core
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initializes all non-hub devices in the "on" level. Some
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drivers may change this setting when they are bound.
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This file is deprecated.
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Use the power/control file instead; it does exactly the
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same thing.
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