This patch (as884) finally implements the time-saving semantics possible with the Power Management FREEZE and PRETHAW events. Their proper handling requires only that devices be quiesced, with interrupts and DMA turned off; non-root USB devices don't actually need to be put in a suspended state. The patch checks and avoids doing the suspend call when possible.
Signed-off-by: Alan Stern <[EMAIL PROTECTED]> --- Index: usb-2.6/drivers/usb/core/generic.c =================================================================== --- usb-2.6.orig/drivers/usb/core/generic.c +++ usb-2.6/drivers/usb/core/generic.c @@ -193,10 +193,6 @@ static void generic_disconnect(struct us static int generic_suspend(struct usb_device *udev, pm_message_t msg) { - /* USB devices enter SUSPEND state through their hubs, but can be - * marked for FREEZE as soon as their children are already idled. - * But those semantics are useless, so we equate the two (sigh). - */ return usb_port_suspend(udev); } Index: usb-2.6/drivers/usb/core/driver.c =================================================================== --- usb-2.6.orig/drivers/usb/core/driver.c +++ usb-2.6/drivers/usb/core/driver.c @@ -1043,8 +1043,15 @@ static int usb_suspend_both(struct usb_d break; } } - if (status == 0) + if (status == 0) { + + /* Non-root devices don't need to do anything for FREEZE + * or PRETHAW. */ + if (udev->parent && (msg.event == PM_EVENT_FREEZE || + msg.event == PM_EVENT_PRETHAW)) + goto done; status = usb_suspend_device(udev, msg); + } /* If the suspend failed, resume interfaces that did get suspended */ if (status != 0) { ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel