USB: don't let errors prevent system sleep
authorAlan Stern <stern@rowland.harvard.edu>
Wed, 15 Jun 2011 20:27:43 +0000 (16:27 -0400)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 16 Jun 2011 00:44:56 +0000 (17:44 -0700)
This patch (as1464) implements the recommended policy that most errors
during suspend or hibernation should not prevent the system from going
to sleep.  In particular, failure to suspend a USB driver or a USB
device should not prevent the sleep from succeeding:

Failure to suspend a device won't matter, because the device will
automatically go into suspend mode when the USB bus stops carrying
packets.  (This might be less true for USB-3.0 devices, but let's not
worry about them now.)

Failure of a driver to suspend might lead to trouble later on when the
system wakes up, but it isn't sufficient reason to prevent the system
from going to sleep.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/driver.c

index e35a17687c05f77b9ecc55b4002d0b13386081b6..81add81ab040a47cde9d75d068800544ddbdecdb 100644 (file)
@@ -1187,13 +1187,22 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
                for (i = n - 1; i >= 0; --i) {
                        intf = udev->actconfig->interface[i];
                        status = usb_suspend_interface(udev, intf, msg);
+
+                       /* Ignore errors during system sleep transitions */
+                       if (!(msg.event & PM_EVENT_AUTO))
+                               status = 0;
                        if (status != 0)
                                break;
                }
        }
-       if (status == 0)
+       if (status == 0) {
                status = usb_suspend_device(udev, msg);
 
+               /* Again, ignore errors during system sleep transitions */
+               if (!(msg.event & PM_EVENT_AUTO))
+                       status = 0;
+       }
+
        /* If the suspend failed, resume interfaces that did get suspended */
        if (status != 0) {
                msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);