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Commit 6ee0b270 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: simplify hub_restart() logic 



This patch (as1081) straightens out the logic of the hub_restart()
routine.  Each port of the hub is scanned and the driver makes sure
that ports which are supposed to be disabled really _are_ disabled.
Any ports with a significant change in status are flagged in
hub->change_bits, so that khubd can focus on them without the need to
scan all the ports a second time -- which means the hub->activating
flag is no longer needed.

Also, it is now recognized explicitly that the only reason for
resuming a port which was not suspended is to carry out a reset-resume
operation, which happens only in a non-CONFIG_USB_SUSPEND setting.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 9e5eace7

drivers/usb/core/driver.c

+1 −6
Original line number Diff line number Diff line
@@ -805,8 +805,6 @@ static int usb_resume_device(struct usb_device *udev) 


	if (udev->state == USB_STATE_NOTATTACHED)

		goto done;

	if (udev->state != USB_STATE_SUSPENDED && !udev->reset_resume)

		goto done;



	/* Can't resume it if it doesn't have a driver. */

	if (udev->dev.driver == NULL) {
@@ -1173,11 +1171,8 @@ static int usb_resume_both(struct usb_device *udev) 
			 * then we're stuck. */

			status = usb_resume_device(udev);

		}

	} else {



		/* Needed for reset-resume */

	} else if (udev->reset_resume)

		status = usb_resume_device(udev);

	}



	if (status == 0 && udev->actconfig) {

		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {

drivers/usb/core/hub.c

+53 −61
Original line number Diff line number Diff line
@@ -72,7 +72,6 @@ struct usb_hub { 


	unsigned		limited_power:1;

	unsigned		quiescing:1;

	unsigned		activating:1;

	unsigned		disconnected:1;



	unsigned		has_indicators:1;
@@ -539,7 +538,6 @@ static void hub_quiesce(struct usb_hub *hub) 
{

	/* (nonblocking) khubd and related activity won't re-trigger */

	hub->quiescing = 1;

	hub->activating = 0;



	/* (blocking) stop khubd and related activity */

	usb_kill_urb(hub->urb);
@@ -554,7 +552,6 @@ static void hub_activate(struct usb_hub *hub) 
	int	status;



	hub->quiescing = 0;

	hub->activating = 1;



	status = usb_submit_urb(hub->urb, GFP_NOIO);

	if (status < 0)
@@ -638,81 +635,83 @@ static void hub_stop(struct usb_hub *hub) 
	hub_quiesce(hub);

}



#define HUB_RESET		1

#define HUB_RESUME		2

#define HUB_RESET_RESUME	3



#ifdef CONFIG_PM

enum hub_activation_type {

	HUB_INIT, HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME

};



static void hub_restart(struct usb_hub *hub, int type)

static void hub_restart(struct usb_hub *hub, enum hub_activation_type type)

{

	struct usb_device *hdev = hub->hdev;

	int port1;



	/* Check each of the children to see if they require

	 * USB-PERSIST handling or disconnection.  Also check

	 * each unoccupied port to make sure it is still disabled.

	/* Check each port and set hub->change_bits to let khubd know

	 * which ports need attention.

	 */

	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {

		struct usb_device *udev = hdev->children[port1-1];

		int status = 0;

		int status;

		u16 portstatus, portchange;



		if (!udev || udev->state == USB_STATE_NOTATTACHED) {

			if (type != HUB_RESET) {

				status = hub_port_status(hub, port1,

						&portstatus, &portchange);

				if (status == 0 && (portstatus &

						USB_PORT_STAT_ENABLE))

					clear_port_feature(hdev, port1,

							USB_PORT_FEAT_ENABLE);

			}

			continue;

		portstatus = portchange = 0;

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

		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))

			dev_dbg(hub->intfdev,

					"port %d: status %04x change %04x\n",

					port1, portstatus, portchange);



		/* After anything other than HUB_RESUME (i.e., initialization

		 * or any sort of reset), every port should be disabled.

		 * Unconnected ports should likewise be disabled (paranoia),

		 * and so should ports for which we have no usb_device.

		 */

		if ((portstatus & USB_PORT_STAT_ENABLE) && (

				type != HUB_RESUME ||

				!(portstatus & USB_PORT_STAT_CONNECTION) ||

				!udev ||

				udev->state == USB_STATE_NOTATTACHED)) {

			clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);

			portstatus &= ~USB_PORT_STAT_ENABLE;

		}



		/* Was the power session lost while we were suspended? */

		switch (type) {

		case HUB_RESET_RESUME:

			portstatus = 0;

			portchange = USB_PORT_STAT_C_CONNECTION;

			break;

		if (!udev || udev->state == USB_STATE_NOTATTACHED) {

			/* Tell khubd to disconnect the device or

			 * check for a new connection

			 */

			if (udev || (portstatus & USB_PORT_STAT_CONNECTION))

				set_bit(port1, hub->change_bits);



		case HUB_RESET:

		case HUB_RESUME:

			status = hub_port_status(hub, port1,

					&portstatus, &portchange);

			break;

		}

		} else if (portstatus & USB_PORT_STAT_ENABLE) {

			/* The power session apparently survived the resume.

			 * If there was an overcurrent or suspend change

			 * (i.e., remote wakeup request), have khubd

			 * take care of it.

			 */

			if (portchange)

				set_bit(port1, hub->change_bits);



		/* For "USB_PERSIST"-enabled children we must

		 * mark the child device for reset-resume and

		 * turn off the various status changes to prevent

		 * khubd from disconnecting it later.

		} else if (udev->persist_enabled) {

			/* Turn off the status changes to prevent khubd

			 * from disconnecting the device.

			 */

		if (udev->persist_enabled && status == 0 &&

				!(portstatus & USB_PORT_STAT_ENABLE)) {

			if (portchange & USB_PORT_STAT_C_ENABLE)

				clear_port_feature(hub->hdev, port1,

						USB_PORT_FEAT_C_ENABLE);

			if (portchange & USB_PORT_STAT_C_CONNECTION)

				clear_port_feature(hub->hdev, port1,

						USB_PORT_FEAT_C_CONNECTION);

#ifdef CONFIG_PM

			udev->reset_resume = 1;

#endif

		} else {

			/* The power session is gone; tell khubd */

			usb_set_device_state(udev, USB_STATE_NOTATTACHED);

			set_bit(port1, hub->change_bits);

		}



		/* Otherwise for a reset_resume we must disconnect the child,

		 * but as we may not lock the child device here

		 * we have to do a "logical" disconnect.

		 */

		else if (type == HUB_RESET_RESUME)

			hub_port_logical_disconnect(hub, port1);

	}



	hub_activate(hub);

}



#endif	/* CONFIG_PM */



/* caller has locked the hub device */

static int hub_pre_reset(struct usb_interface *intf)

{
@@ -728,7 +727,7 @@ static int hub_post_reset(struct usb_interface *intf) 
	struct usb_hub *hub = usb_get_intfdata(intf);



	hub_power_on(hub);

	hub_activate(hub);

	hub_restart(hub, HUB_POST_RESET);

	return 0;

}
@@ -2903,7 +2902,7 @@ static void hub_events(void) 
				continue;

			connect_change = test_bit(i, hub->change_bits);

			if (!test_and_clear_bit(i, hub->event_bits) &&

					!connect_change && !hub->activating)

					!connect_change)

				continue;



			ret = hub_port_status(hub, i,
@@ -2911,11 +2910,6 @@ static void hub_events(void) 
			if (ret < 0)

				continue;



			if (hub->activating && !hdev->children[i-1] &&

					(portstatus &

						USB_PORT_STAT_CONNECTION))

				connect_change = 1;



			if (portchange & USB_PORT_STAT_C_CONNECTION) {

				clear_port_feature(hdev, i,

					USB_PORT_FEAT_C_CONNECTION);
@@ -3011,8 +3005,6 @@ static void hub_events(void) 
			}

		}



		hub->activating = 0;



		/* If this is a root hub, tell the HCD it's okay to

		 * re-enable port-change interrupts now. */

		if (!hdev->parent && !hub->busy_bits[0])