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Commit 2caf7fcd authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: re-enable interface after driver unbinds 



This patch (as1197) fixes an error introduced recently.  Since a
significant number of devices can't handle Set-Interface requests, we
no longer call usb_set_interface() when a driver unbinds from an
interface, provided the interface is already in altsetting 0.  However
the interface still does get disabled, and the call to
usb_set_interface() was the only thing re-enabling it.  Since the
interface doesn't get re-enabled, further attempts to use it fail.

So the patch adds a call to usb_enable_interface() when a driver
unbinds and the interface is in altsetting 0.  For this to work
right, the interface's endpoints have to be re-enabled but their
toggles have to be left alone.  Therefore an additional argument is
added to usb_enable_endpoint() and usb_enable_interface(), a flag
indicating whether or not the endpoint toggles should be reset.

This is a forward-ported version of a patch which fixes Bugzilla
#12301.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-by: default avatarDavid Roka <roka@dawid.hu>
Reported-by: default avatarErik Ekman <erik@kryo.se>
Tested-by: default avatarErik Ekman <erik@kryo.se>
Tested-by: default avatarAlon Bar-Lev <alon.barlev@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent df718962

drivers/usb/core/driver.c

+6 −3
Original line number Diff line number Diff line
@@ -295,9 +295,12 @@ static int usb_unbind_interface(struct device *dev) 
	 * altsetting means creating new endpoint device entries).

	 * When either of these happens, defer the Set-Interface.

	 */

	if (intf->cur_altsetting->desc.bAlternateSetting == 0)

		;	/* Already in altsetting 0 so skip Set-Interface */

	else if (!error && intf->dev.power.status == DPM_ON)

	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {

		/* Already in altsetting 0 so skip Set-Interface.

		 * Just re-enable it without affecting the endpoint toggles.

		 */

		usb_enable_interface(udev, intf, false);

	} else if (!error && intf->dev.power.status == DPM_ON)

		usb_set_interface(udev, intf->altsetting[0].

				desc.bInterfaceNumber, 0);

	else

drivers/usb/core/hub.c

+1 −1
Original line number Diff line number Diff line
@@ -2384,7 +2384,7 @@ void usb_ep0_reinit(struct usb_device *udev) 
{

	usb_disable_endpoint(udev, 0 + USB_DIR_IN);

	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);

	usb_enable_endpoint(udev, &udev->ep0);

	usb_enable_endpoint(udev, &udev->ep0, true);

}

EXPORT_SYMBOL_GPL(usb_ep0_reinit);

drivers/usb/core/message.c

+15 −10
Original line number Diff line number Diff line
@@ -1143,21 +1143,25 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0) 
 * usb_enable_endpoint - Enable an endpoint for USB communications

 * @dev: the device whose interface is being enabled

 * @ep: the endpoint

 * @reset_toggle: flag to set the endpoint's toggle back to 0

 *

 * Resets the endpoint toggle, and sets dev->ep_{in,out} pointers.

 * Resets the endpoint toggle if asked, and sets dev->ep_{in,out} pointers.

 * For control endpoints, both the input and output sides are handled.

 */

void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep)

void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,

		bool reset_toggle)

{

	int epnum = usb_endpoint_num(&ep->desc);

	int is_out = usb_endpoint_dir_out(&ep->desc);

	int is_control = usb_endpoint_xfer_control(&ep->desc);



	if (is_out || is_control) {

		if (reset_toggle)

			usb_settoggle(dev, epnum, 1, 0);

		dev->ep_out[epnum] = ep;

	}

	if (!is_out || is_control) {

		if (reset_toggle)

			usb_settoggle(dev, epnum, 0, 0);

		dev->ep_in[epnum] = ep;

	}
@@ -1168,17 +1172,18 @@ void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep) 
 * usb_enable_interface - Enable all the endpoints for an interface

 * @dev: the device whose interface is being enabled

 * @intf: pointer to the interface descriptor

 * @reset_toggles: flag to set the endpoints' toggles back to 0

 *

 * Enables all the endpoints for the interface's current altsetting.

 */

static void usb_enable_interface(struct usb_device *dev,

				 struct usb_interface *intf)

void usb_enable_interface(struct usb_device *dev,

		struct usb_interface *intf, bool reset_toggles)

{

	struct usb_host_interface *alt = intf->cur_altsetting;

	int i;



	for (i = 0; i < alt->desc.bNumEndpoints; ++i)

		usb_enable_endpoint(dev, &alt->endpoint[i]);

		usb_enable_endpoint(dev, &alt->endpoint[i], reset_toggles);

}



/**
@@ -1303,7 +1308,7 @@ int usb_set_interface(struct usb_device *dev, int interface, int alternate) 
	 * during the SETUP stage - hence EP0 toggles are "don't care" here.

	 * (Likewise, EP0 never "halts" on well designed devices.)

	 */

	usb_enable_interface(dev, iface);

	usb_enable_interface(dev, iface, true);

	if (device_is_registered(&iface->dev)) {

		usb_create_sysfs_intf_files(iface);

		create_intf_ep_devs(iface);
@@ -1382,7 +1387,7 @@ int usb_reset_configuration(struct usb_device *dev) 
			usb_remove_sysfs_intf_files(intf);

		}

		intf->cur_altsetting = alt;

		usb_enable_interface(dev, intf);

		usb_enable_interface(dev, intf, true);

		if (device_is_registered(&intf->dev)) {

			usb_create_sysfs_intf_files(intf);

			create_intf_ep_devs(intf);
@@ -1685,7 +1690,7 @@ free_interfaces: 
			alt = &intf->altsetting[0];



		intf->cur_altsetting = alt;

		usb_enable_interface(dev, intf);

		usb_enable_interface(dev, intf, true);

		intf->dev.parent = &dev->dev;

		intf->dev.driver = NULL;

		intf->dev.bus = &usb_bus_type;

drivers/usb/core/usb.c

+1 −1
Original line number Diff line number Diff line
@@ -362,7 +362,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, 
	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;

	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;

	/* ep0 maxpacket comes later, from device descriptor */

	usb_enable_endpoint(dev, &dev->ep0);

	usb_enable_endpoint(dev, &dev->ep0, true);

	dev->can_submit = 1;



	/* Save readable and stable topology id, distinguishing devices

drivers/usb/core/usb.h

+3 −1
Original line number Diff line number Diff line
@@ -12,7 +12,9 @@ extern int usb_create_ep_devs(struct device *parent, 
extern void usb_remove_ep_devs(struct usb_host_endpoint *endpoint);



extern void usb_enable_endpoint(struct usb_device *dev,

		struct usb_host_endpoint *ep);

		struct usb_host_endpoint *ep, bool reset_toggle);

extern void usb_enable_interface(struct usb_device *dev,

		struct usb_interface *intf, bool reset_toggles);

extern void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr);

extern void usb_disable_interface(struct usb_device *dev,

		struct usb_interface *intf);