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| author |   Alan Stern <stern@rowland.harvard.edu> | 2007-10-10 16:30:12 -0400 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@suse.de> | 2007-10-12 14:55:34 -0700 |
| commit | 271f9e68f3450ac8d1ff3bda36581f1ec0d0cc1f (patch) | |
| tree | 245f6895f988086686fe338b0097fe9b99f1c9f9 /drivers/usb | |
| parent | USB: mutual exclusion for EHCI init and port resets (diff) | |
| download | linux-dev-271f9e68f3450ac8d1ff3bda36581f1ec0d0cc1f.tar.xz linux-dev-271f9e68f3450ac8d1ff3bda36581f1ec0d0cc1f.zip | |
USB: skip autosuspended devices during system resume
System suspends and hibernation are supposed to be as transparent as
possible. By this reasoning, if a USB device is already autosuspended
before the system sleep begins then it should remain autosuspended
after the system wakes up.
This patch (as1001) adds a skip_sys_resume flag to the usb_device
structure and uses it to avoid waking up devices which were suspended
when a system sleep began.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/core/driver.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 3f734240e0ec..8c1eac27f2de 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1540,9 +1540,21 @@ int usb_external_resume_device(struct usb_device *udev) static int usb_suspend(struct device *dev, pm_message_t message) { + struct usb_device *udev; + if (!is_usb_device(dev)) /* Ignore PM for interfaces */ return 0; - return usb_external_suspend_device(to_usb_device(dev), message); + udev = to_usb_device(dev); + + /* If udev is already suspended, we can skip this suspend and + * we should also skip the upcoming system resume. */ + if (udev->state == USB_STATE_SUSPENDED) { + udev->skip_sys_resume = 1; + return 0; + } + + udev->skip_sys_resume = 0; + return usb_external_suspend_device(udev, message); } static int usb_resume(struct device *dev) @@ -1553,13 +1565,14 @@ static int usb_resume(struct device *dev) return 0; udev = to_usb_device(dev); - /* If autoresume is disabled then we also want to prevent resume - * during system wakeup. However, a "persistent-device" reset-resume - * after power loss counts as a wakeup event. So allow a - * reset-resume to occur if remote wakeup is enabled. */ - if (udev->autoresume_disabled) { + /* If udev->skip_sys_resume is set then udev was already suspended + * when the system suspend started, so we don't want to resume + * udev during this system wakeup. However a reset-resume counts + * as a wakeup event, so allow a reset-resume to occur if remote + * wakeup is enabled. */ + if (udev->skip_sys_resume) { if (!(udev->reset_resume && udev->do_remote_wakeup)) - return -EPERM; + return -EHOSTUNREACH; } return usb_external_resume_device(udev); } |