usbcore: add autosuspend/autoresume infrastructure
This patch (as739) adds the basic infrastructure for USB autosuspend
and autoresume. The main features are:
PM usage counters added to struct usb_device and struct
usb_interface, indicating whether it's okay to autosuspend
them or they are currently in use.
Flag added to usb_device indicating whether the current
suspend/resume operation originated from outside or as an
autosuspend/autoresume.
Flag added to usb_driver indicating whether the driver
supports autosuspend. If not, no device bound to the driver
will be autosuspended.
Mutex added to usb_device for protecting PM operations.
Unlike the device semaphore, the locking rule for the pm_mutex
is that you must acquire the locks going _up_ the device tree.
New routines handling autosuspend/autoresume requests for
interfaces and devices.
Suspend and resume requests are propagated up the device tree
(but not outside the USB subsystem).
work_struct added to usb_device, for carrying out delayed
autosuspend requests.
Autoresume added (and autosuspend prevented) during probe and
disconnect.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 78e910b..dee812b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1017,19 +1017,22 @@
if (udev->state == USB_STATE_NOTATTACHED)
; /* do nothing */
else if (new_state != USB_STATE_NOTATTACHED) {
- udev->state = new_state;
/* root hub wakeup capabilities are managed out-of-band
* and may involve silicon errata ... ignore them here.
*/
if (udev->parent) {
- if (new_state == USB_STATE_CONFIGURED)
+ if (udev->state == USB_STATE_SUSPENDED
+ || new_state == USB_STATE_SUSPENDED)
+ ; /* No change to wakeup settings */
+ else if (new_state == USB_STATE_CONFIGURED)
device_init_wakeup(&udev->dev,
(udev->actconfig->desc.bmAttributes
& USB_CONFIG_ATT_WAKEUP));
- else if (new_state != USB_STATE_SUSPENDED)
+ else
device_init_wakeup(&udev->dev, 0);
}
+ udev->state = new_state;
} else
recursively_mark_NOTATTACHED(udev);
spin_unlock_irqrestore(&device_state_lock, flags);
@@ -1507,7 +1510,7 @@
* NOTE: OTG devices may issue remote wakeup (or SRP) even when
* we don't explicitly enable it here.
*/
- if (device_may_wakeup(&udev->dev)) {
+ if (udev->do_remote_wakeup) {
status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
USB_DEVICE_REMOTE_WAKEUP, 0,
@@ -1533,7 +1536,8 @@
USB_CTRL_SET_TIMEOUT);
} else {
/* device has up to 10 msec to fully suspend */
- dev_dbg(&udev->dev, "usb suspend\n");
+ dev_dbg(&udev->dev, "usb %ssuspend\n",
+ udev->auto_pm ? "auto-" : "");
usb_set_device_state(udev, USB_STATE_SUSPENDED);
msleep(10);
}
@@ -1573,7 +1577,8 @@
status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
udev);
else {
- dev_dbg(&udev->dev, "usb suspend\n");
+ dev_dbg(&udev->dev, "usb %ssuspend\n",
+ udev->auto_pm ? "auto-" : "");
usb_set_device_state(udev, USB_STATE_SUSPENDED);
}
return status;
@@ -1687,7 +1692,8 @@
/* drive resume for at least 20 msec */
if (udev)
- dev_dbg(&udev->dev, "RESUME\n");
+ dev_dbg(&udev->dev, "usb %sresume\n",
+ udev->auto_pm ? "auto-" : "");
msleep(25);
#define LIVE_FLAGS ( USB_PORT_STAT_POWER \
@@ -1754,8 +1760,11 @@
// NOTE this fails if parent is also suspended...
status = hub_port_resume(hdev_to_hub(udev->parent),
udev->portnum, udev);
- } else
+ } else {
+ dev_dbg(&udev->dev, "usb %sresume\n",
+ udev->auto_pm ? "auto-" : "");
status = finish_port_resume(udev);
+ }
if (status < 0)
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
return status;
@@ -1765,19 +1774,23 @@
{
int status = 0;
- /* don't repeat RESUME sequence if this device
- * was already woken up by some other task
- */
+ /* All this just to avoid sending a port-resume message
+ * to the parent hub! */
+
usb_lock_device(udev);
+ mutex_lock_nested(&udev->pm_mutex, udev->level);
if (udev->state == USB_STATE_SUSPENDED) {
- dev_dbg(&udev->dev, "RESUME (wakeup)\n");
+ dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
/* TRSMRCY = 10 msec */
msleep(10);
status = finish_port_resume(udev);
+ if (status == 0)
+ udev->dev.power.power_state.event = PM_EVENT_ON;
}
+ mutex_unlock(&udev->pm_mutex);
if (status == 0)
- usb_resume_both(udev);
+ usb_autoresume_device(udev, 0);
usb_unlock_device(udev);
return status;
}
@@ -1834,7 +1847,9 @@
== PM_EVENT_ON
#endif
) {
- dev_dbg(&intf->dev, "port %d nyet suspended\n", port1);
+ if (!hdev->auto_pm)
+ dev_dbg(&intf->dev, "port %d nyet suspended\n",
+ port1);
return -EBUSY;
}
}
@@ -2587,7 +2602,7 @@
* stub "device" node was never suspended.
*/
if (i)
- usb_resume_both(hdev);
+ usb_autoresume_device(hdev, 0);
/* If this is an inactive or suspended hub, do nothing */
if (hub->quiescing)
@@ -2993,6 +3008,9 @@
return -EINVAL;
}
+ /* Prevent autosuspend during the reset */
+ usb_autoresume_device(udev, 1);
+
if (iface && iface->condition != USB_INTERFACE_BINDING)
iface = NULL;
@@ -3034,6 +3052,7 @@
}
}
+ usb_autosuspend_device(udev, 1);
return ret;
}
EXPORT_SYMBOL(usb_reset_composite_device);