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| author | Alan Stern <stern@rowland.harvard.edu> | 2007-05-30 23:39:33 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-13 03:34:30 +0400 |
| commit | b41a60eca833d76593d4dac8a59f5c38714194ee (patch) | |
| tree | a7c5cf721d9978503c3c8c88183747cf954b8733 /Documentation/ABI/testing/sysfs-bus-usb | |
| parent | 54515fe528d8c6f9bfaf7d0b9fffb908deecad78 (diff) | |
| download | linux-b41a60eca833d76593d4dac8a59f5c38714194ee.tar.xz | |
USB: add power/persist device attribute
This patch (as920) adds an extra level of protection to the
USB-Persist facility. Now it will apply by default only to hubs; for
all other devices the user must enable it explicitly by setting the
power/persist device attribute.
The disconnect_all_children() routine in hub.c has been removed and
its code placed inline. This is the way it was originally as part of
hub_pre_reset(); the revised usage in hub_reset_resume() is
sufficiently different that the code can no longer be shared.
Likewise, mark_children_for_reset() is now inline as part of
hub_reset_resume(). The end result looks much cleaner than before.
The sysfs interface is updated to add the new attribute file, and
there are corresponding documentation updates.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-usb')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index f9937add033d..9734577d1711 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -39,3 +39,16 @@ Description: 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. + +What: /sys/bus/usb/devices/.../power/persist +Date: May 2007 +KernelVersion: 2.6.23 +Contact: Alan Stern <stern@rowland.harvard.edu> +Description: + If CONFIG_USB_PERSIST is set, then each USB device directory + will contain a file named power/persist. The file holds a + boolean value (0 or 1) indicating whether or not the + "USB-Persist" facility is enabled for the device. Since the + facility is inherently dangerous, it is disabled by default + for all devices except hubs. For more information, see + Documentation/usb/persist.txt. |