USB: add USB-Persist facility

This patch (as886) adds the controversial USB-persist facility,
allowing USB devices to persist across a power loss during system
suspend.

The facility is controlled by a new Kconfig option (with appropriate
warnings about the potential dangers); when the option is off the
behavior will remain the same as it is now.  But when the option is
on, people will be able to use suspend-to-disk and keep their USB
filesystems intact -- something particularly valuable for small
machines where the root filesystem is on a USB device!

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2007-05-04 11:52:20 -04:00
committed by Greg Kroah-Hartman
parent ce7cd137fc
commit 0458d5b4c9
10 changed files with 353 additions and 79 deletions

View File

@@ -217,7 +217,10 @@ static int generic_resume(struct usb_device *udev)
{
int rc;
rc = usb_port_resume(udev);
if (udev->reset_resume)
rc = usb_reset_suspended_device(udev);
else
rc = usb_port_resume(udev);
/* Root hubs don't have upstream ports to resume or reset,
* so the line above won't do much for them. We have to