From 2caf7fcdb8532045680f06b67b9e63f0c9613aaa Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 31 Dec 2008 11:31:33 -0500 Subject: [PATCH] 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: Alan Stern Reported-by: David Roka Reported-by: Erik Ekman Tested-by: Erik Ekman Tested-by: Alon Bar-Lev Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 9 ++++++--- drivers/usb/core/hub.c | 2 +- drivers/usb/core/message.c | 25 +++++++++++++++---------- drivers/usb/core/usb.c | 2 +- drivers/usb/core/usb.h | 4 +++- 5 files changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 41c06025506..98760553bc9 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -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 diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 756b8d9993f..d5d0e40b1e2 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -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); diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 5589686981f..de51667dd64 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1143,22 +1143,26 @@ 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) { - usb_settoggle(dev, epnum, 1, 0); + if (reset_toggle) + usb_settoggle(dev, epnum, 1, 0); dev->ep_out[epnum] = ep; } if (!is_out || is_control) { - usb_settoggle(dev, epnum, 0, 0); + if (reset_toggle) + usb_settoggle(dev, epnum, 0, 0); dev->ep_in[epnum] = ep; } ep->enabled = 1; @@ -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; diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index c0821564a3f..dcfc072630c 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -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 diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 381eae90c3b..386177867a8 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -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); -- 2.41.1