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Commit 5340ba82 authored by Linus Torvalds's avatar Linus Torvalds Committed by Greg Kroah-Hartman
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USB: don't use reset-resume if drivers don't support it 



This patch tries to identify which devices are able to accept
reset-resume handling, by checking that there is at least one
interface driver bound and that all of the drivers have a reset_resume
method defined.  If these conditions don't hold then during resume
processing, the device is logicall disconnected.

This is only a temporary fix.  Later on we will explicitly unbind
drivers that can't handle reset-resumes.

Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e6942d63

drivers/usb/core/hub.c

+44 −2
Original line number Original line Diff line number Diff line
@@ -644,6 +644,48 @@ static void hub_stop(struct usb_hub *hub) 




#ifdef CONFIG_PM

#ifdef CONFIG_PM





/* Try to identify which devices need USB-PERSIST handling */

static int persistent_device(struct usb_device *udev)

{

	int i;

	int retval;

	struct usb_host_config *actconfig;



	/* Explicitly not marked persistent? */

	if (!udev->persist_enabled)

		return 0;



	/* No active config? */

	actconfig = udev->actconfig;

	if (!actconfig)

		return 0;



	/* FIXME! We should check whether it's open here or not! */



	/*

	 * Check that all the interface drivers have a

	 * 'reset_resume' entrypoint

	 */

	retval = 0;

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

		struct usb_interface *intf;

		struct usb_driver *driver;



		intf = actconfig->interface[i];

		if (!intf->dev.driver)

			continue;

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

		if (!driver->reset_resume)

			return 0;

		/*

		 * We have at least one driver, and that one

		 * has a reset_resume method.

		 */

		retval = 1;

	}

	return retval;

}



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

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

{

{

	struct usb_device *hdev = hub->hdev;

	struct usb_device *hdev = hub->hdev;
@@ -689,8 +731,8 @@ static void hub_restart(struct usb_hub *hub, int type) 
		 * turn off the various status changes to prevent

		 * turn off the various status changes to prevent

		 * khubd from disconnecting it later.

		 * khubd from disconnecting it later.

		 */

		 */

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

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

				!(portstatus & USB_PORT_STAT_ENABLE)) {

				persistent_device(udev)) {

			if (portchange & USB_PORT_STAT_C_ENABLE)

			if (portchange & USB_PORT_STAT_C_ENABLE)

				clear_port_feature(hub->hdev, port1,

				clear_port_feature(hub->hdev, port1,

						USB_PORT_FEAT_C_ENABLE);

						USB_PORT_FEAT_C_ENABLE);