From af4f76066d0fcb215ae389b8839d7ae37ce0e28b Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 30 Oct 2006 17:06:45 -0500 Subject: [PATCH] USB: autosuspend code consolidation 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 112 +++++++++++++++++++++++++++------------------- 1 file changed, 67 insertions(+), 45 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 401d76f..ca0e40e 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -940,6 +940,36 @@ done: 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; -- 2.7.4