diff options
| -rw-r--r-- | drivers/usb/core/devices.c | 4 | ||||
| -rw-r--r-- | drivers/usb/core/devio.c | 2 | ||||
| -rw-r--r-- | drivers/usb/core/driver.c | 4 | ||||
| -rw-r--r-- | drivers/usb/core/hcd.c | 5 | ||||
| -rw-r--r-- | drivers/usb/core/hub.c | 48 | ||||
| -rw-r--r-- | drivers/usb/core/usb.c | 114 | ||||
| -rw-r--r-- | drivers/usb/core/usb.h | 3 | ||||
| -rw-r--r-- | drivers/usb/host/ohci-hub.c | 2 | ||||
| -rw-r--r-- | include/linux/usb.h | 9 |
9 files changed, 37 insertions, 154 deletions
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c index 83e815d3cd52..55bc563a3256 100644 --- a/drivers/usb/core/devices.c +++ b/drivers/usb/core/devices.c @@ -545,10 +545,10 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, loff_t *ski struct usb_device *childdev = usbdev->children[chix]; if (childdev) { - down(&childdev->serialize); + usb_lock_device(childdev); ret = usb_device_dump(buffer, nbytes, skip_bytes, file_offset, childdev, bus, level + 1, chix, ++cnt); - up(&childdev->serialize); + usb_unlock_device(childdev); if (ret == -EFAULT) return total_written; total_written += ret; diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 3a73170e95dd..2b68998fe4b3 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1349,9 +1349,7 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl) /* let kernel drivers try to (re)bind to the interface */ case USBDEVFS_CONNECT: usb_unlock_device(ps->dev); - usb_lock_all_devices(); bus_rescan_devices(intf->dev.bus); - usb_unlock_all_devices(); usb_lock_device(ps->dev); break; diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index bb139f06bcd6..076462c8ba2a 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -432,9 +432,7 @@ int usb_register_driver(struct usb_driver *new_driver, struct module *owner) spin_lock_init(&new_driver->dynids.lock); INIT_LIST_HEAD(&new_driver->dynids.list); - usb_lock_all_devices(); retval = driver_register(&new_driver->driver); - usb_unlock_all_devices(); if (!retval) { pr_info("%s: registered new driver %s\n", @@ -465,11 +463,9 @@ void usb_deregister(struct usb_driver *driver) { pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name); - usb_lock_all_devices(); usb_remove_newid_file(driver); usb_free_dynids(driver); driver_unregister(&driver->driver); - usb_unlock_all_devices(); usbfs_update_special(); } diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index da24c31ee00d..d16a0e8a7d72 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -857,9 +857,7 @@ static int register_root_hub (struct usb_device *usb_dev, return (retval < 0) ? retval : -EMSGSIZE; } - usb_lock_device (usb_dev); retval = usb_new_device (usb_dev); - usb_unlock_device (usb_dev); if (retval) { usb_dev->bus->root_hub = NULL; dev_err (parent_dev, "can't register root hub for %s, %d\n", @@ -1891,7 +1889,10 @@ void usb_remove_hcd(struct usb_hcd *hcd) spin_lock_irq (&hcd_root_hub_lock); hcd->rh_registered = 0; spin_unlock_irq (&hcd_root_hub_lock); + + down(&usb_bus_list_lock); usb_disconnect(&hcd->self.root_hub); + up(&usb_bus_list_lock); hcd->poll_rh = 0; del_timer_sync(&hcd->rh_timer); diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 40c6c50c6bd9..dd3bcfb2bcb6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -32,7 +32,7 @@ #include "hub.h" /* Protect struct usb_device->state and ->children members - * Note: Both are also protected by ->serialize, except that ->state can + * Note: Both are also protected by ->dev.sem, except that ->state can * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */ static DEFINE_SPINLOCK(device_state_lock); @@ -975,8 +975,8 @@ static int locktree(struct usb_device *udev) /* when everyone grabs locks top->bottom, * non-overlapping work may be concurrent */ - down(&udev->serialize); - up(&hdev->serialize); + usb_lock_device(udev); + usb_unlock_device(hdev); return t + 1; } } @@ -1132,16 +1132,10 @@ void usb_disconnect(struct usb_device **pdev) * this quiesces everyting except pending urbs. */ usb_set_device_state(udev, USB_STATE_NOTATTACHED); - - /* lock the bus list on behalf of HCDs unregistering their root hubs */ - if (!udev->parent) { - down(&usb_bus_list_lock); - usb_lock_device(udev); - } else - down(&udev->serialize); - dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum); + usb_lock_device(udev); + /* Free up all the children before we remove this device */ for (i = 0; i < USB_MAXCHILDREN; i++) { if (udev->children[i]) @@ -1169,11 +1163,7 @@ void usb_disconnect(struct usb_device **pdev) *pdev = NULL; spin_unlock_irq(&device_state_lock); - if (!udev->parent) { - usb_unlock_device(udev); - up(&usb_bus_list_lock); - } else - up(&udev->serialize); + usb_unlock_device(udev); device_unregister(&udev->dev); } @@ -1243,8 +1233,8 @@ static inline void show_string(struct usb_device *udev, char *id, char *string) * * This is called with devices which have been enumerated, but not yet * configured. The device descriptor is available, but not descriptors - * for any device configuration. The caller must have locked udev and - * either the parent hub (if udev is a normal device) or else the + * for any device configuration. The caller must have locked either + * the parent hub (if udev is a normal device) or else the * usb_bus_list_lock (if udev is a root hub). The parent's pointer to * udev has already been installed, but udev is not yet visible through * sysfs or other filesystem code. @@ -1254,8 +1244,7 @@ static inline void show_string(struct usb_device *udev, char *id, char *string) * * This call is synchronous, and may not be used in an interrupt context. * - * Only the hub driver should ever call this; root hub registration - * uses it indirectly. + * Only the hub driver or root-hub registrar should ever call this. */ int usb_new_device(struct usb_device *udev) { @@ -1364,6 +1353,8 @@ int usb_new_device(struct usb_device *udev) } usb_create_sysfs_dev_files (udev); + usb_lock_device(udev); + /* choose and set the configuration. that registers the interfaces * with the driver core, and lets usb device drivers bind to them. */ @@ -1385,6 +1376,8 @@ int usb_new_device(struct usb_device *udev) /* USB device state == configured ... usable */ usb_notify_add_device(udev); + usb_unlock_device(udev); + return 0; fail: @@ -1872,11 +1865,8 @@ int usb_resume_device(struct usb_device *udev) usb_unlock_device(udev); /* rebind drivers that had no suspend() */ - if (status == 0) { - usb_lock_all_devices(); + if (status == 0) bus_rescan_devices(&usb_bus_type); - usb_unlock_all_devices(); - } return status; } @@ -1889,14 +1879,14 @@ static int remote_wakeup(struct usb_device *udev) /* don't repeat RESUME sequence if this device * was already woken up by some other task */ - down(&udev->serialize); + usb_lock_device(udev); if (udev->state == USB_STATE_SUSPENDED) { dev_dbg(&udev->dev, "RESUME (wakeup)\n"); /* TRSMRCY = 10 msec */ msleep(10); status = finish_device_resume(udev); } - up(&udev->serialize); + usb_unlock_device(udev); #endif return status; } @@ -1997,7 +1987,7 @@ static int hub_resume(struct usb_interface *intf) if (!udev || status < 0) continue; - down (&udev->serialize); + usb_lock_device(udev); if (portstat & USB_PORT_STAT_SUSPEND) status = hub_port_resume(hub, port1, udev); else { @@ -2008,7 +1998,7 @@ static int hub_resume(struct usb_interface *intf) hub_port_logical_disconnect(hub, port1); } } - up(&udev->serialize); + usb_unlock_device(udev); } } #endif @@ -2573,7 +2563,6 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, * udev becomes globally accessible, although presumably * no one will look at it until hdev is unlocked. */ - down (&udev->serialize); status = 0; /* We mustn't add new devices if the parent hub has @@ -2597,7 +2586,6 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, } } - up (&udev->serialize); if (status) goto loop_disable; diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 294e9f127477..fcfda21be499 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -32,7 +32,6 @@ #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> @@ -49,8 +48,6 @@ const char *usbcore_name = "usbcore"; static int nousb; /* Disable USB when built into kernel image */ /* Not honored on modular build */ -static DECLARE_RWSEM(usb_all_devices_rwsem); - /** * usb_ifnum_to_if - get the interface object with a given interface number @@ -446,8 +443,6 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) dev->parent = parent; INIT_LIST_HEAD(&dev->filelist); - init_MUTEX(&dev->serialize); - return dev; } @@ -520,76 +515,21 @@ void usb_put_intf(struct usb_interface *intf) /* 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(). + * USB devices and interfaces are locked using the semaphore in their + * embedded struct device. The hub driver guarantees that whenever a + * device is connected or disconnected, drivers are called with the + * USB device locked as well as their particular interface. * * 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(). + * do this; nobody else needs to worry about it. The rule for locking + * is simple: * * 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 @@ -627,7 +567,7 @@ int usb_lock_device_for_reset(struct usb_device *udev, } } - while (!usb_trylock_device(udev)) { + while (usb_trylock_device(udev) != 0) { /* If we can't acquire the lock after waiting one second, * we're probably deadlocked */ @@ -645,39 +585,6 @@ int usb_lock_device_for_reset(struct usb_device *udev, 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) @@ -700,10 +607,10 @@ static struct usb_device *match_device(struct usb_device *dev, /* 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); + usb_lock_device(dev->children[child]); ret_dev = match_device(dev->children[child], vendor_id, product_id); - up(&dev->children[child]->serialize); + usb_unlock_device(dev->children[child]); if (ret_dev) goto exit; } @@ -1300,10 +1207,7 @@ EXPORT_SYMBOL(usb_put_dev); 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); diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 98e85fb4d3b7..4647e1ebc68d 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -16,9 +16,6 @@ extern int usb_get_device_descriptor(struct usb_device *dev, extern char *usb_cache_string(struct usb_device *udev, int index); extern int usb_set_configuration(struct usb_device *dev, int configuration); -extern void usb_lock_all_devices(void); -extern void usb_unlock_all_devices(void); - extern void usb_kick_khubd(struct usb_device *dev); extern void usb_suspend_root_hub(struct usb_device *hdev); extern void usb_resume_root_hub(struct usb_device *dev); diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c index 72e3b12a1926..4b2226d77b34 100644 --- a/drivers/usb/host/ohci-hub.c +++ b/drivers/usb/host/ohci-hub.c @@ -372,7 +372,7 @@ done: & ohci->hc_control) == OHCI_USB_OPER && time_after (jiffies, ohci->next_statechange) - && usb_trylock_device (hcd->self.root_hub) + && usb_trylock_device (hcd->self.root_hub) == 0 ) { ohci_vdbg (ohci, "autosuspend\n"); (void) ohci_bus_suspend (hcd); diff --git a/include/linux/usb.h b/include/linux/usb.h index 2714814ab66c..46dc0421d19e 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -329,8 +329,6 @@ struct usb_device { struct usb_tt *tt; /* low/full speed dev, highspeed hub */ int ttport; /* device port on that tt hub */ - struct semaphore serialize; - unsigned int toggle[2]; /* one bit for each endpoint * ([0] = IN, [1] = OUT) */ @@ -377,11 +375,12 @@ struct usb_device { extern struct usb_device *usb_get_dev(struct usb_device *dev); extern void usb_put_dev(struct usb_device *dev); -extern void usb_lock_device(struct usb_device *udev); -extern int usb_trylock_device(struct usb_device *udev); +/* USB device locking */ +#define usb_lock_device(udev) down(&(udev)->dev.sem) +#define usb_unlock_device(udev) up(&(udev)->dev.sem) +#define usb_trylock_device(udev) down_trylock(&(udev)->dev.sem) extern int usb_lock_device_for_reset(struct usb_device *udev, struct usb_interface *iface); -extern void usb_unlock_device(struct usb_device *udev); /* USB port reset for device reinitialization */ extern int usb_reset_device(struct usb_device *dev); |
