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path: root/Documentation/usb/persist.txt
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2008-07-22USB: use reset_resume when normal resume failsAlan Stern1-2/+5
This patch (as1109b) makes USB-Persist more resilient to errors. With the current code, if a normal resume fails, it's an unrecoverable error. With the patch, if a normal resume fails (and if the device is enabled for USB-Persist) then a reset-resume is tried. This fixes the problem reported in Bugzilla #10977. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-25USB: check serial-number string after device resetAlan Stern1-4/+4
This patch (as1048) extends the descriptor checking after a device is reset. Now the SerialNumber string descriptor is compared to its old value, in addition to the device and configuration descriptors. As a consequence, the kmalloc() call in usb_string() is now on the error-handling pathway for usb-storage. Hence its allocation type is changed to GFO_NOIO. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-25USB: remove CONFIG_USB_PERSIST settingAlan Stern1-16/+19
This patch (as1047) removes the USB_PERSIST Kconfig option, enabling it permanently. It also prevents the power/persist attribute from being created for hub devices; there's no point in having it since USB-PERSIST is always turned on for hubs. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-13USB: add power/persist device attributeAlan Stern1-13/+25
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>
2007-07-13USB: add USB-Persist facilityAlan Stern1-0/+144
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>