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USB: autosuspend code consolidation

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This patch (as813) gathers together common code for USB interface
autosuspend/autoresume. 

It also adds some simple checking at the time an autosuspend request
is made, to see whether the request will fail.  This way we don't
add a workqueue entry when it would end up doing nothing.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2006-10-30 17:06:45 -05:00 committed by Greg Kroah-Hartman
parent 0c1ac4f25f
commit af4f76066d
1 changed files with 67 additions and 45 deletions
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112
drivers/usb/core/driver.c
View file

@ -940,6 +940,36 @@ static int resume_interface(struct usb_interface *intf)
return status;
}
/* Internal routine to check whether we may autosuspend a device. */
static int autosuspend_check(struct usb_device *udev)
{
int i;
struct usb_interface *intf;
/* For autosuspend, fail fast if anything is in use.
* Also fail if any interfaces require remote wakeup but it
* isn't available. */
udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
if (udev->pm_usage_cnt > 0)
return -EBUSY;
if (udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
if (!is_active(intf))
continue;
if (intf->pm_usage_cnt > 0)
return -EBUSY;
if (intf->needs_remote_wakeup &&
!udev->do_remote_wakeup) {
dev_dbg(&udev->dev, "remote wakeup needed "
"for autosuspend\n");
return -EOPNOTSUPP;
}
}
}
return 0;
}
/**
* usb_suspend_both - suspend a USB device and its interfaces
* @udev: the usb_device to suspend
@ -991,28 +1021,10 @@ int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
/* For autosuspend, fail fast if anything is in use.
* Also fail if any interfaces require remote wakeup but it
* isn't available. */
if (udev->auto_pm) {
if (udev->pm_usage_cnt > 0)
return -EBUSY;
if (udev->actconfig) {
for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
intf = udev->actconfig->interface[i];
if (!is_active(intf))
continue;
if (intf->pm_usage_cnt > 0)
return -EBUSY;
if (intf->needs_remote_wakeup &&
!udev->do_remote_wakeup) {
dev_dbg(&udev->dev,
"remote wakeup needed for autosuspend\n");
return -EOPNOTSUPP;
}
}
i = 0;
}
status = autosuspend_check(udev);
if (status < 0)
return status;
}
/* Suspend all the interfaces and then udev itself */
@ -1151,7 +1163,7 @@ void usb_autosuspend_device(struct usb_device *udev, int dec_usage_cnt)
{
usb_pm_lock(udev);
udev->pm_usage_cnt -= dec_usage_cnt;
if (udev->pm_usage_cnt <= 0)
if (autosuspend_check(udev) == 0)
queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
USB_AUTOSUSPEND_DELAY);
usb_pm_unlock(udev);
@ -1200,6 +1212,33 @@ int usb_autoresume_device(struct usb_device *udev, int inc_usage_cnt)
return status;
}
/* Internal routine to adjust an interface's usage counter and change
* its device's autosuspend state.
*/
static int usb_autopm_do_interface(struct usb_interface *intf,
int inc_usage_cnt)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status = 0;
usb_pm_lock(udev);
if (intf->condition == USB_INTERFACE_UNBOUND)
status = -ENODEV;
else {
intf->pm_usage_cnt += inc_usage_cnt;
if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
udev->auto_pm = 1;
status = usb_resume_both(udev);
if (status != 0)
intf->pm_usage_cnt -= inc_usage_cnt;
} else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0)
queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
USB_AUTOSUSPEND_DELAY);
}
usb_pm_unlock(udev);
return status;
}
/**
* usb_autopm_put_interface - decrement a USB interface's PM-usage counter
* @intf: the usb_interface whose counter should be decremented
@ -1233,17 +1272,11 @@ int usb_autoresume_device(struct usb_device *udev, int inc_usage_cnt)
*/
void usb_autopm_put_interface(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status;
usb_pm_lock(udev);
if (intf->condition != USB_INTERFACE_UNBOUND &&
--intf->pm_usage_cnt <= 0) {
queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
USB_AUTOSUSPEND_DELAY);
}
usb_pm_unlock(udev);
// dev_dbg(&intf->dev, "%s: cnt %d\n",
// __FUNCTION__, intf->pm_usage_cnt);
status = usb_autopm_do_interface(intf, -1);
// dev_dbg(&intf->dev, "%s: status %d cnt %d\n",
// __FUNCTION__, status, intf->pm_usage_cnt);
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
@ -1280,20 +1313,9 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
*/
int usb_autopm_get_interface(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status;
int status;
usb_pm_lock(udev);
if (intf->condition == USB_INTERFACE_UNBOUND)
status = -ENODEV;
else {
++intf->pm_usage_cnt;
udev->auto_pm = 1;
status = usb_resume_both(udev);
if (status != 0)
--intf->pm_usage_cnt;
}
usb_pm_unlock(udev);
status = usb_autopm_do_interface(intf, 1);
// dev_dbg(&intf->dev, "%s: status %d cnt %d\n",
// __FUNCTION__, status, intf->pm_usage_cnt);
return status;