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Commit d25450c6 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB hub: simplify remote-wakeup handling 



This patch (as817) simplifies the remote-wakeup processing in the hub
driver.  Now instead of using a specialized code path, it relies on
the standard USB resume routines.  The hub_port_resume() function does
an initial get_port_status() to see whether the port has already
resumed itself (as it does when a remote-wakeup request is sent).
This will slow down handling of other resume events slightly, but not
enough to matter.

The patch also changes the hub_port_status() routine, making it return
an error if a short reply is received.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ce361587

drivers/usb/core/hub.c

+20 −23
Original line number Diff line number Diff line
@@ -1409,10 +1409,12 @@ static int hub_port_status(struct usb_hub *hub, int port1, 
	int ret;



	ret = get_port_status(hub->hdev, port1, &hub->status->port);

	if (ret < 0)

	if (ret < 4) {

		dev_err (hub->intfdev,

			"%s failed (err = %d)\n", __FUNCTION__, ret);

	else {

		if (ret >= 0)

			ret = -EIO;

	} else {

		*status = le16_to_cpu(hub->status->port.wPortStatus);

		*change = le16_to_cpu(hub->status->port.wPortChange); 

		ret = 0;
@@ -1760,6 +1762,12 @@ static int 
hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)

{

	int	status;

	u16	portchange, portstatus;



	/* Skip the initial Clear-Suspend step for a remote wakeup */

	status = hub_port_status(hub, port1, &portstatus, &portchange);

	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))

		goto SuspendCleared;



	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
@@ -1773,9 +1781,6 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev) 
			"can't resume port %d, status %d\n",

			port1, status);

	} else {

		u16		devstatus;

		u16		portchange;



		/* drive resume for at least 20 msec */

		if (udev)

			dev_dbg(&udev->dev, "usb %sresume\n",
@@ -1790,16 +1795,15 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev) 
		 * stop resume signaling.  Then finish the resume

		 * sequence.

		 */

		devstatus = portchange = 0;

		status = hub_port_status(hub, port1,

				&devstatus, &portchange);

		status = hub_port_status(hub, port1, &portstatus, &portchange);

SuspendCleared:

		if (status < 0

				|| (devstatus & LIVE_FLAGS) != LIVE_FLAGS

				|| (devstatus & USB_PORT_STAT_SUSPEND) != 0

				|| (portstatus & LIVE_FLAGS) != LIVE_FLAGS

				|| (portstatus & USB_PORT_STAT_SUSPEND) != 0

				) {

			dev_dbg(hub->intfdev,

				"port %d status %04x.%04x after resume, %d\n",

				port1, portchange, devstatus, status);

				port1, portchange, portstatus, status);

			if (status >= 0)

				status = -ENODEV;

		} else {
@@ -1860,23 +1864,16 @@ static int remote_wakeup(struct usb_device *udev) 
{

	int	status = 0;



	/* All this just to avoid sending a port-resume message

	 * to the parent hub! */



	usb_lock_device(udev);

	usb_pm_lock(udev);

	if (udev->state == USB_STATE_SUSPENDED) {

		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;

	}

	usb_pm_unlock(udev);

		status = usb_autoresume_device(udev, 1);



		/* Give the interface drivers a chance to do something,

		 * then autosuspend the device again. */

		if (status == 0)

		usb_autoresume_device(udev, 0);

			usb_autosuspend_device(udev, 1);

	}

	usb_unlock_device(udev);

	return status;

}