Commit f07600cf authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

USB: add reset_resume method 



This patch (as918) introduces a new USB driver method: reset_resume.
It is called when a device needs to be reset as part of a resume
procedure (whether because of a device quirk or because of the
USB-Persist facility), thereby taking over a role formerly assigned to
the post_reset method.  As a consequence, post_reset no longer needs
an argument indicating whether it is being called as part of a
reset-resume.  This separation of functions makes the code clearer.

In addition, the pre_reset and post_reset method return types are
changed; they now must return an error code.  The return value is
unused at present, but at some later time we may unbind drivers and
re-probe if they encounter an error during reset handling.

The existing pre_reset and post_reset methods in the usbhid,
usb-storage, and hub drivers are updated to match the new
requirements.  For usbhid the post_reset routine is also used for
reset_resume (duplicate method pointers); for the other drivers a new
reset_resume routine is added.  The change to hub.c looks bigger than
it really is, because mark_children_for_reset_resume() gets moved down
next to the new hub_reset_resume() routine.

A minor change to usb-storage makes the usb_stor_report_bus_reset()
routine acquire the host lock instead of requiring the caller to hold
it already.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 624d6c07

drivers/hid/usbhid/hid-core.c

+6 −3
Original line number Diff line number Diff line
@@ -1009,20 +1009,22 @@ static int hid_resume(struct usb_interface *intf) 
}



/* Treat USB reset pretty much the same as suspend/resume */

static void hid_pre_reset(struct usb_interface *intf)

static int hid_pre_reset(struct usb_interface *intf)

{

	/* FIXME: What if the interface is already suspended? */

	hid_suspend(intf, PMSG_ON);

	return 0;

}



static void hid_post_reset(struct usb_interface *intf, int reset_resume)

/* Same routine used for post_reset and reset_resume */

static int hid_post_reset(struct usb_interface *intf)

{

	struct usb_device *dev = interface_to_usbdev (intf);



	hid_set_idle(dev, intf->cur_altsetting->desc.bInterfaceNumber, 0, 0);

	/* FIXME: Any more reinitialization needed? */



	hid_resume(intf);

	return hid_resume(intf);

}



static struct usb_device_id hid_usb_ids [] = {
@@ -1039,6 +1041,7 @@ static struct usb_driver hid_driver = { 
	.disconnect =	hid_disconnect,

	.suspend =	hid_suspend,

	.resume =	hid_resume,

	.reset_resume =	hid_post_reset,

	.pre_reset =	hid_pre_reset,

	.post_reset =	hid_post_reset,

	.id_table =	hid_usb_ids,

drivers/usb/core/driver.c

+40 −11
Original line number Diff line number Diff line
@@ -915,21 +915,37 @@ static int usb_resume_interface(struct usb_interface *intf, int reset_resume) 
	}

	driver = to_usb_driver(intf->dev.driver);



	if (reset_resume && driver->post_reset)

		driver->post_reset(intf, reset_resume);

	else if (driver->resume) {

	if (reset_resume) {

		if (driver->reset_resume) {

			status = driver->reset_resume(intf);

			if (status)

				dev_err(&intf->dev, "%s error %d\n",

						"reset_resume", status);

		} else {

			// status = -EOPNOTSUPP;

			dev_warn(&intf->dev, "no %s for driver %s?\n",

					"reset_resume", driver->name);

		}

	} else {

		if (driver->resume) {

			status = driver->resume(intf);

			if (status)

				dev_err(&intf->dev, "%s error %d\n",

						"resume", status);

	} else

		dev_warn(&intf->dev, "no resume for driver %s?\n",

				driver->name);

		} else {

			// status = -EOPNOTSUPP;

			dev_warn(&intf->dev, "no %s for driver %s?\n",

					"resume", driver->name);

		}

	}



done:

	dev_vdbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status);

	if (status == 0)

		mark_active(intf);



	/* FIXME: Unbind the driver and reprobe if the resume failed

	 * (not possible if auto_pm is set) */

	return status;

}
@@ -966,6 +982,18 @@ static int autosuspend_check(struct usb_device *udev) 
						"for autosuspend\n");

				return -EOPNOTSUPP;

			}



			/* Don't allow autosuspend if the device will need

			 * a reset-resume and any of its interface drivers

			 * doesn't include support.

			 */

			if (udev->quirks & USB_QUIRK_RESET_RESUME) {

				struct usb_driver *driver;



				driver = to_usb_driver(intf->dev.driver);

				if (!driver->reset_resume)

					return -EOPNOTSUPP;

			}

		}

	}
@@ -1146,7 +1174,8 @@ static int usb_resume_both(struct usb_device *udev) 
			status = usb_autoresume_device(parent);

			if (status == 0) {

				status = usb_resume_device(udev);

				if (status) {

				if (status || udev->state ==

						USB_STATE_NOTATTACHED) {

					usb_autosuspend_device(parent);



					/* It's possible usb_resume_device()

drivers/usb/core/hub.c

+63 −54
Original line number Diff line number Diff line
@@ -605,73 +605,26 @@ static void disconnect_all_children(struct usb_hub *hub, int logical) 
	}

}



#ifdef	CONFIG_USB_PERSIST



#define USB_PERSIST	1



/* For "persistent-device" resets we must mark the child devices for reset

 * and turn off a possible connect-change status (so khubd won't disconnect

 * them later).

 */

static void mark_children_for_reset_resume(struct usb_hub *hub)

{

	struct usb_device *hdev = hub->hdev;

	int port1;



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

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



		if (child) {

			child->reset_resume = 1;

			clear_port_feature(hdev, port1,

					USB_PORT_FEAT_C_CONNECTION);

		}

	}

}



#else



#define USB_PERSIST	0



static inline void mark_children_for_reset_resume(struct usb_hub *hub)

{ }



#endif	/* CONFIG_USB_PERSIST */



/* caller has locked the hub device */

static void hub_pre_reset(struct usb_interface *intf)

static int hub_pre_reset(struct usb_interface *intf)

{

	struct usb_hub *hub = usb_get_intfdata(intf);



	/* This routine doesn't run as part of a reset-resume, so it's safe

	 * to disconnect all the drivers below the hub.

	 */

	disconnect_all_children(hub, 0);

	hub_quiesce(hub);

	return 0;

}



/* caller has locked the hub device */

static void hub_post_reset(struct usb_interface *intf, int reset_resume)

static int hub_post_reset(struct usb_interface *intf)

{

	struct usb_hub *hub = usb_get_intfdata(intf);



	hub_power_on(hub);

	if (reset_resume) {

		if (USB_PERSIST)

			mark_children_for_reset_resume(hub);

		else {

			/* Reset-resume doesn't call pre_reset, so we have to

			 * disconnect the children here.  But we may not lock

			 * the child devices, so we have to do a "logical"

			 * disconnect.

			 */

			disconnect_all_children(hub, 1);

		}

	}

	hub_activate(hub);

	return 0;

}





static int hub_configure(struct usb_hub *hub,

	struct usb_endpoint_descriptor *endpoint)

{
@@ -1931,6 +1884,58 @@ static int hub_resume(struct usb_interface *intf) 
	return 0;

}



#ifdef	CONFIG_USB_PERSIST



#define USB_PERSIST	1



/* For "persistent-device" resets we must mark the child devices for reset

 * and turn off a possible connect-change status (so khubd won't disconnect

 * them later).

 */

static void mark_children_for_reset_resume(struct usb_hub *hub)

{

	struct usb_device *hdev = hub->hdev;

	int port1;



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

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



		if (child) {

			child->reset_resume = 1;

			clear_port_feature(hdev, port1,

					USB_PORT_FEAT_C_CONNECTION);

		}

	}

}



#else



#define USB_PERSIST	0



static inline void mark_children_for_reset_resume(struct usb_hub *hub)

{ }



#endif	/* CONFIG_USB_PERSIST */



static int hub_reset_resume(struct usb_interface *intf)

{

	struct usb_hub *hub = usb_get_intfdata(intf);



	hub_power_on(hub);

	if (USB_PERSIST)

		mark_children_for_reset_resume(hub);

	else {

		/* Reset-resume doesn't call pre_reset, so we have to

		 * disconnect the children here.  But we may not lock

		 * the child devices, so we have to do a "logical"

		 * disconnect.

		 */

		disconnect_all_children(hub, 1);

	}

	hub_activate(hub);

	return 0;

}



#else	/* CONFIG_PM */



static inline int remote_wakeup(struct usb_device *udev)
@@ -1940,6 +1945,7 @@ static inline int remote_wakeup(struct usb_device *udev) 


#define hub_suspend		NULL

#define hub_resume		NULL

#define hub_reset_resume	NULL

#endif
@@ -2768,6 +2774,7 @@ static struct usb_driver hub_driver = { 
	.disconnect =	hub_disconnect,

	.suspend =	hub_suspend,

	.resume =	hub_resume,

	.reset_resume =	hub_reset_resume,

	.pre_reset =	hub_pre_reset,

	.post_reset =	hub_post_reset,

	.ioctl =	hub_ioctl,
@@ -3021,6 +3028,7 @@ int usb_reset_composite_device(struct usb_device *udev, 
				drv = to_usb_driver(cintf->dev.driver);

				if (drv->pre_reset)

					(drv->pre_reset)(cintf);

	/* FIXME: Unbind if pre_reset returns an error or isn't defined */

			}

		}

	}
@@ -3038,7 +3046,8 @@ int usb_reset_composite_device(struct usb_device *udev, 
					cintf->dev.driver) {

				drv = to_usb_driver(cintf->dev.driver);

				if (drv->post_reset)

					(drv->post_reset)(cintf, 0);

					(drv->post_reset)(cintf);

	/* FIXME: Unbind if post_reset returns an error or isn't defined */

			}

			if (cintf != iface)

				up(&cintf->dev.sem);

drivers/usb/storage/scsiglue.c

+6 −2
Original line number Diff line number Diff line
@@ -321,10 +321,14 @@ void usb_stor_report_device_reset(struct us_data *us) 


/* Report a driver-initiated bus reset to the SCSI layer.

 * Calling this for a SCSI-initiated reset is unnecessary but harmless.

 * The caller must own the SCSI host lock. */

 * The caller must not own the SCSI host lock. */

void usb_stor_report_bus_reset(struct us_data *us)

{

	scsi_report_bus_reset(us_to_host(us), 0);

	struct Scsi_Host *host = us_to_host(us);



	scsi_lock(host);

	scsi_report_bus_reset(host, 0);

	scsi_unlock(host);

}



/***********************************************************************

drivers/usb/storage/usb.c

+20 −8
Original line number Diff line number Diff line
@@ -219,6 +219,20 @@ static int storage_resume(struct usb_interface *iface) 
	return 0;

}



static int storage_reset_resume(struct usb_interface *iface)

{

	struct us_data *us = usb_get_intfdata(iface);



	US_DEBUGP("%s\n", __FUNCTION__);



	/* Report the reset to the SCSI core */

	usb_stor_report_bus_reset(us);



	/* FIXME: Notify the subdrivers that they need to reinitialize

	 * the device */

	return 0;

}



#endif /* CONFIG_PM */



/*
@@ -226,7 +240,7 @@ static int storage_resume(struct usb_interface *iface) 
 * a USB port reset, whether from this driver or a different one.

 */



static void storage_pre_reset(struct usb_interface *iface)

static int storage_pre_reset(struct usb_interface *iface)

{

	struct us_data *us = usb_get_intfdata(iface);
@@ -234,26 +248,23 @@ static void storage_pre_reset(struct usb_interface *iface) 


	/* Make sure no command runs during the reset */

	mutex_lock(&us->dev_mutex);

	return 0;

}



static void storage_post_reset(struct usb_interface *iface, int reset_resume)

static int storage_post_reset(struct usb_interface *iface)

{

	struct us_data *us = usb_get_intfdata(iface);



	US_DEBUGP("%s\n", __FUNCTION__);



	/* Report the reset to the SCSI core */

	scsi_lock(us_to_host(us));

	usb_stor_report_bus_reset(us);

	scsi_unlock(us_to_host(us));



	/* FIXME: Notify the subdrivers that they need to reinitialize

	 * the device */



	/* If this is a reset-resume then the pre_reset routine wasn't

	 * called, so we don't need to unlock the mutex. */

	if (!reset_resume)

	mutex_unlock(&us->dev_mutex);

	return 0;

}



/*
@@ -1061,6 +1072,7 @@ static struct usb_driver usb_storage_driver = { 
#ifdef CONFIG_PM

	.suspend =	storage_suspend,

	.resume =	storage_resume,

	.reset_resume =	storage_reset_resume,

#endif

	.pre_reset =	storage_pre_reset,

	.post_reset =	storage_post_reset,

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