diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2007-05-04 11:52:20 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 16:29:47 -0700 |
| commit | 0458d5b4c9cc4ca0f62625d0144ddc4b4bc97a3c (patch) | |
| tree | 8b1fcb4f063ef4aa6f2e3cd41a60d986a1e432d4 /drivers/usb/core/Kconfig | |
| parent | ce7cd137fced114d49178b73d468b82096a107fb (diff) | |
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>
Diffstat (limited to 'drivers/usb/core/Kconfig')
| -rw-r--r-- | drivers/usb/core/Kconfig | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig index 346fc030c92..5113ef4cb7f 100644 --- a/drivers/usb/core/Kconfig +++ b/drivers/usb/core/Kconfig @@ -86,6 +86,28 @@ config USB_SUSPEND If you are unsure about this, say N here. +config USB_PERSIST + bool "USB device persistence during system suspend (DANGEROUS)" + depends on USB && PM && EXPERIMENTAL + default n + help + If you say Y here, USB device data structures will remain + persistent across system suspend, even if the USB bus loses + power. (This includes software-suspend, also known as swsusp, + or suspend-to-disk.) The devices will reappear as if by magic + when the system wakes up, with no need to unmount USB filesystems, + rmmod host-controller drivers, or do anything else. + + WARNING: This option can be dangerous! + + If a USB device is replaced by another of the same type while + the system is asleep, there's a good chance the kernel won't + detect the change. Likewise if the media in a USB storage + device is replaced. When this happens it's almost certain to + cause data corruption and maybe even crash your system. + + If you are unsure, say N here. + config USB_OTG bool depends on USB && EXPERIMENTAL |