#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
-#include <linux/rwsem.h>
#include <linux/usb.h>
#include <asm/io.h>
int nousb; /* Disable USB when built into kernel image */
/* Not honored on modular build */
-DECLARE_RWSEM(usb_all_devices_rwsem);
-EXPORT_SYMBOL(usb_all_devices_rwsem);
-
static int generic_probe (struct device *dev)
{
}
static struct device_driver usb_generic_driver = {
- .owner = THIS_MODULE,
.name = "usb",
.bus = &usb_bus_type,
.probe = generic_probe,
if (!driver->probe)
return error;
- /* FIXME we'd much prefer to just resume it ... */
if (interface_to_usbdev(intf)->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
id = usb_match_id (intf, driver->id_table);
if (id) {
dev_dbg (dev, "%s - got id\n", __FUNCTION__);
- intf->condition = USB_INTERFACE_BINDING;
error = driver->probe (intf, id);
- intf->condition = error ? USB_INTERFACE_UNBOUND :
- USB_INTERFACE_BOUND;
}
return error;
struct usb_interface *intf = to_usb_interface(dev);
struct usb_driver *driver = to_usb_driver(intf->dev.driver);
- intf->condition = USB_INTERFACE_UNBINDING;
-
/* release all urbs for this interface */
usb_disable_interface(interface_to_usbdev(intf), intf);
intf->altsetting[0].desc.bInterfaceNumber,
0);
usb_set_intfdata(intf, NULL);
- intf->condition = USB_INTERFACE_UNBOUND;
return 0;
}
new_driver->driver.bus = &usb_bus_type;
new_driver->driver.probe = usb_probe_interface;
new_driver->driver.remove = usb_unbind_interface;
- new_driver->driver.owner = new_driver->owner;
- usb_lock_all_devices();
retval = driver_register(&new_driver->driver);
- usb_unlock_all_devices();
if (!retval) {
pr_info("%s: registered new driver %s\n",
{
pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name);
- usb_lock_all_devices();
driver_unregister (&driver->driver);
- usb_unlock_all_devices();
usbfs_update_special();
}
* alternate settings available for this interfaces.
*
* Don't call this function unless you are bound to one of the interfaces
- * on this device or you have locked the device!
+ * on this device or you own the dev->serialize semaphore!
*/
struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum)
{
* drivers avoid such mistakes.
*
* Don't call this function unless you are bound to the intf interface
- * or you have locked the device!
+ * or you own the device's ->serialize semaphore!
*/
struct usb_host_interface *usb_altnum_to_altsetting(struct usb_interface *intf,
unsigned int altnum)
* way to bind to an interface is to return the private data from
* the driver's probe() method.
*
- * Callers must own the device lock and the driver model's usb_bus_type.subsys
- * writelock. So driver probe() entries don't need extra locking,
- * but other call contexts may need to explicitly claim those locks.
+ * Callers must own the driver model's usb bus writelock. So driver
+ * probe() entries don't need extra locking, but other call contexts
+ * may need to explicitly claim that lock.
*/
-int usb_driver_claim_interface(struct usb_driver *driver,
- struct usb_interface *iface, void* priv)
+int usb_driver_claim_interface(struct usb_driver *driver, struct usb_interface *iface, void* priv)
{
struct device *dev = &iface->dev;
dev->driver = &driver->driver;
usb_set_intfdata(iface, priv);
- iface->condition = USB_INTERFACE_BOUND;
/* if interface was already added, bind now; else let
* the future device_add() bind it, bypassing probe()
* also causes the driver disconnect() method to be called.
*
* This call is synchronous, and may not be used in an interrupt context.
- * Callers must own the device lock and the driver model's usb_bus_type.subsys
- * writelock. So driver disconnect() entries don't need extra locking,
+ * Callers must own the usb_device serialize semaphore and the driver model's
+ * usb bus writelock. So driver disconnect() entries don't need extra locking,
* but other call contexts may need to explicitly claim those locks.
*/
void usb_driver_release_interface(struct usb_driver *driver,
dev->driver = NULL;
usb_set_intfdata(iface, NULL);
- iface->condition = USB_INTERFACE_UNBOUND;
}
/**
return 0;
intf = to_usb_interface(dev);
+
usb_drv = to_usb_driver(drv);
+ id = usb_drv->id_table;
id = usb_match_id (intf, usb_drv->id_table);
if (id)
{
struct usb_interface *intf;
struct usb_device *usb_dev;
+ char *scratch;
int i = 0;
int length = 0;
return -ENODEV;
}
+ scratch = buffer;
+
#ifdef CONFIG_USB_DEVICEFS
/* If this is available, userspace programs can directly read
* all the device descriptors we don't tell them about. Or
*
* FIXME reduce hardwired intelligence here
*/
- if (add_hotplug_env_var(envp, num_envp, &i,
- buffer, buffer_size, &length,
- "DEVICE=/proc/bus/usb/%03d/%03d",
- usb_dev->bus->busnum, usb_dev->devnum))
+ envp [i++] = scratch;
+ length += snprintf (scratch, buffer_size - length,
+ "DEVICE=/proc/bus/usb/%03d/%03d",
+ usb_dev->bus->busnum, usb_dev->devnum);
+ if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
+ ++length;
+ scratch += length;
#endif
/* per-device configurations are common */
- if (add_hotplug_env_var(envp, num_envp, &i,
- buffer, buffer_size, &length,
- "PRODUCT=%x/%x/%x",
- usb_dev->descriptor.idVendor,
- usb_dev->descriptor.idProduct,
- usb_dev->descriptor.bcdDevice))
+ envp [i++] = scratch;
+ length += snprintf (scratch, buffer_size - length, "PRODUCT=%x/%x/%x",
+ usb_dev->descriptor.idVendor,
+ usb_dev->descriptor.idProduct,
+ usb_dev->descriptor.bcdDevice);
+ if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
+ ++length;
+ scratch += length;
/* class-based driver binding models */
- if (add_hotplug_env_var(envp, num_envp, &i,
- buffer, buffer_size, &length,
- "TYPE=%d/%d/%d",
- usb_dev->descriptor.bDeviceClass,
- usb_dev->descriptor.bDeviceSubClass,
- usb_dev->descriptor.bDeviceProtocol))
+ envp [i++] = scratch;
+ length += snprintf (scratch, buffer_size - length, "TYPE=%d/%d/%d",
+ usb_dev->descriptor.bDeviceClass,
+ usb_dev->descriptor.bDeviceSubClass,
+ usb_dev->descriptor.bDeviceProtocol);
+ if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
+ ++length;
+ scratch += length;
if (usb_dev->descriptor.bDeviceClass == 0) {
struct usb_host_interface *alt = intf->cur_altsetting;
* agents are called for all interfaces, and can use
* $DEVPATH/bInterfaceNumber if necessary.
*/
- if (add_hotplug_env_var(envp, num_envp, &i,
- buffer, buffer_size, &length,
- "INTERFACE=%d/%d/%d",
- alt->desc.bInterfaceClass,
- alt->desc.bInterfaceSubClass,
- alt->desc.bInterfaceProtocol))
+ envp [i++] = scratch;
+ length += snprintf (scratch, buffer_size - length,
+ "INTERFACE=%d/%d/%d",
+ alt->desc.bInterfaceClass,
+ alt->desc.bInterfaceSubClass,
+ alt->desc.bInterfaceProtocol);
+ if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
- }
+ ++length;
+ scratch += length;
- envp[i] = NULL;
+ }
+ envp[i++] = NULL;
return 0;
}
init_MUTEX(&dev->serialize);
if (dev->bus->op->allocate)
- if (dev->bus->op->allocate(dev)) {
- usb_bus_put(bus);
- kfree(dev);
- return NULL;
- }
+ dev->bus->op->allocate(dev);
return dev;
}
put_device(&intf->dev);
}
-
-/* USB device locking
- *
- * Although locking USB devices should be straightforward, it is
- * complicated by the way the driver-model core works. When a new USB
- * driver is registered or unregistered, the core will automatically
- * probe or disconnect all matching interfaces on all USB devices while
- * holding the USB subsystem writelock. There's no good way for us to
- * tell which devices will be used or to lock them beforehand; our only
- * option is to effectively lock all the USB devices.
- *
- * We do that by using a private rw-semaphore, usb_all_devices_rwsem.
- * When locking an individual device you must first acquire the rwsem's
- * readlock. When a driver is registered or unregistered the writelock
- * must be held. These actions are encapsulated in the subroutines
- * below, so all a driver needs to do is call usb_lock_device() and
- * usb_unlock_device().
- *
- * Complications arise when several devices are to be locked at the same
- * time. Only hub-aware drivers that are part of usbcore ever have to
- * do this; nobody else needs to worry about it. The problem is that
- * usb_lock_device() must not be called to lock a second device since it
- * would acquire the rwsem's readlock reentrantly, leading to deadlock if
- * another thread was waiting for the writelock. The solution is simple:
- *
- * When locking more than one device, call usb_lock_device()
- * to lock the first one. Lock the others by calling
- * down(&udev->serialize) directly.
- *
- * When unlocking multiple devices, use up(&udev->serialize)
- * to unlock all but the last one. Unlock the last one by
- * calling usb_unlock_device().
- *
- * When locking both a device and its parent, always lock the
- * the parent first.
- */
-
-/**
- * usb_lock_device - acquire the lock for a usb device structure
- * @udev: device that's being locked
- *
- * Use this routine when you don't hold any other device locks;
- * to acquire nested inner locks call down(&udev->serialize) directly.
- * This is necessary for proper interaction with usb_lock_all_devices().
- */
-void usb_lock_device(struct usb_device *udev)
-{
- down_read(&usb_all_devices_rwsem);
- down(&udev->serialize);
-}
-
-/**
- * usb_trylock_device - attempt to acquire the lock for a usb device structure
- * @udev: device that's being locked
- *
- * Don't use this routine if you already hold a device lock;
- * use down_trylock(&udev->serialize) instead.
- * This is necessary for proper interaction with usb_lock_all_devices().
- *
- * Returns 1 if successful, 0 if contention.
- */
-int usb_trylock_device(struct usb_device *udev)
-{
- if (!down_read_trylock(&usb_all_devices_rwsem))
- return 0;
- if (down_trylock(&udev->serialize)) {
- up_read(&usb_all_devices_rwsem);
- return 0;
- }
- return 1;
-}
-
-/**
- * usb_lock_device_for_reset - cautiously acquire the lock for a
- * usb device structure
- * @udev: device that's being locked
- * @iface: interface bound to the driver making the request (optional)
- *
- * Attempts to acquire the device lock, but fails if the device is
- * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
- * is neither BINDING nor BOUND. Rather than sleeping to wait for the
- * lock, the routine polls repeatedly. This is to prevent deadlock with
- * disconnect; in some drivers (such as usb-storage) the disconnect()
- * callback will block waiting for a device reset to complete.
- *
- * Returns a negative error code for failure, otherwise 1 or 0 to indicate
- * that the device will or will not have to be unlocked. (0 can be
- * returned when an interface is given and is BINDING, because in that
- * case the driver already owns the device lock.)
- */
-int usb_lock_device_for_reset(struct usb_device *udev,
- struct usb_interface *iface)
-{
- if (udev->state == USB_STATE_NOTATTACHED)
- return -ENODEV;
- if (udev->state == USB_STATE_SUSPENDED)
- return -EHOSTUNREACH;
- if (iface) {
- switch (iface->condition) {
- case USB_INTERFACE_BINDING:
- return 0;
- case USB_INTERFACE_BOUND:
- break;
- default:
- return -EINTR;
- }
- }
-
- while (!usb_trylock_device(udev)) {
- msleep(15);
- if (udev->state == USB_STATE_NOTATTACHED)
- return -ENODEV;
- if (udev->state == USB_STATE_SUSPENDED)
- return -EHOSTUNREACH;
- if (iface && iface->condition != USB_INTERFACE_BOUND)
- return -EINTR;
- }
- return 1;
-}
-
-/**
- * usb_unlock_device - release the lock for a usb device structure
- * @udev: device that's being unlocked
- *
- * Use this routine when releasing the only device lock you hold;
- * to release inner nested locks call up(&udev->serialize) directly.
- * This is necessary for proper interaction with usb_lock_all_devices().
- */
-void usb_unlock_device(struct usb_device *udev)
-{
- up(&udev->serialize);
- up_read(&usb_all_devices_rwsem);
-}
-
-/**
- * usb_lock_all_devices - acquire the lock for all usb device structures
- *
- * This is necessary when registering a new driver or probing a bus,
- * since the driver-model core may try to use any usb_device.
- */
-void usb_lock_all_devices(void)
-{
- down_write(&usb_all_devices_rwsem);
-}
-
-/**
- * usb_unlock_all_devices - release the lock for all usb device structures
- */
-void usb_unlock_all_devices(void)
-{
- up_write(&usb_all_devices_rwsem);
-}
-
-
static struct usb_device *match_device(struct usb_device *dev,
u16 vendor_id, u16 product_id)
{
/* look through all of the children of this device */
for (child = 0; child < dev->maxchild; ++child) {
if (dev->children[child]) {
- down(&dev->children[child]->serialize);
ret_dev = match_device(dev->children[child],
vendor_id, product_id);
- up(&dev->children[child]->serialize);
if (ret_dev)
goto exit;
}
bus = container_of(buslist, struct usb_bus, bus_list);
if (!bus->root_hub)
continue;
- usb_lock_device(bus->root_hub);
dev = match_device(bus->root_hub, vendor_id, product_id);
- usb_unlock_device(bus->root_hub);
if (dev)
goto exit;
}
intf = to_usb_interface(dev);
driver = to_usb_driver(dev->driver);
- /* there's only one USB suspend state */
- if (intf->dev.power.power_state)
- return 0;
-
if (driver->suspend)
return driver->suspend(intf, state);
return 0;
EXPORT_SYMBOL(usb_get_dev);
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
-EXPORT_SYMBOL(usb_lock_device);
-EXPORT_SYMBOL(usb_trylock_device);
-EXPORT_SYMBOL(usb_lock_device_for_reset);
-EXPORT_SYMBOL(usb_unlock_device);
-
EXPORT_SYMBOL(usb_driver_claim_interface);
EXPORT_SYMBOL(usb_driver_release_interface);
EXPORT_SYMBOL(usb_match_id);
git://git.onelab.eu / linux-2.6.git / blobdiff