[PATCH 011/149] USB: Implement PM FREEZE and PRETHAW
Greg Kroah-Hartman <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
From: Alan Stern <[email protected]> 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]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/usb/core/driver.c | 9 ++++++++- drivers/usb/core/generic.c | 4 ---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 38c3dd2..63d4794 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1050,8 +1050,15 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg) 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) { diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index 9bbcb20..e7ec9b6 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -193,10 +193,6 @@ static void generic_disconnect(struct usb_device *udev) 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); } -- 1.5.2.2 ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel