diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2007-05-04 11:51:25 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 16:29:46 -0700 |
| commit | 4d461095ef6967324bc5da5d65d23ad27fc604f9 (patch) | |
| tree | 7b510d94bd7e1351e997504276ccd6e5973b2127 /drivers/usb/core/driver.c | |
| parent | 784a6e1cc406b7ef48476a1f38b83fc551f5616f (diff) | |
USB: Implement PM FREEZE and PRETHAW
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 <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/driver.c')
| -rw-r--r-- | drivers/usb/core/driver.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 38c3dd2a44e..63d47946e3d 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) { |