diff options
| -rw-r--r-- | drivers/base/dd.c | 142 | ||||
| -rw-r--r-- | include/linux/device.h | 1 |
2 files changed, 74 insertions, 69 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index dd2a8a7..8510918 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -35,6 +35,8 @@ * nor take the bus's rwsem. Please verify those are accounted * for before calling this. (It is ok to call with no other effort * from a driver's probe() method.) + * + * This function must be called with @dev->sem held. */ void device_bind_driver(struct device * dev) { @@ -57,54 +59,56 @@ void device_bind_driver(struct device * dev) * because we don't know the format of the ID structures, nor what * is to be considered a match and what is not. * - * If we find a match, we call @drv->probe(@dev) if it exists, and - * call device_bind_driver() above. + * + * This function returns 1 if a match is found, an error if one + * occurs (that is not -ENODEV or -ENXIO), and 0 otherwise. + * + * This function must be called with @dev->sem held. */ -int driver_probe_device(struct device_driver * drv, struct device * dev) +static int driver_probe_device(struct device_driver * drv, struct device * dev) { - int error = 0; + int ret = 0; if (drv->bus->match && !drv->bus->match(dev, drv)) - return -ENODEV; + goto Done; - down(&dev->sem); + pr_debug("%s: Matched Device %s with Driver %s\n", + drv->bus->name, dev->bus_id, drv->name); dev->driver = drv; if (drv->probe) { - error = drv->probe(dev); - if (error) { + ret = drv->probe(dev); + if (ret) { dev->driver = NULL; - up(&dev->sem); - return error; + goto ProbeFailed; } } - up(&dev->sem); device_bind_driver(dev); - return 0; + ret = 1; + pr_debug("%s: Bound Device %s to Driver %s\n", + drv->bus->name, dev->bus_id, drv->name); + goto Done; + + ProbeFailed: + if (ret == -ENODEV || ret == -ENXIO) { + /* Driver matched, but didn't support device + * or device not found. + * Not an error; keep going. + */ + ret = 0; + } else { + /* driver matched but the probe failed */ + printk(KERN_WARNING + "%s: probe of %s failed with error %d\n", + drv->name, dev->bus_id, ret); + } + Done: + return ret; } static int __device_attach(struct device_driver * drv, void * data) { struct device * dev = data; - int error; - - error = driver_probe_device(drv, dev); - if (error) { - if ((error == -ENODEV) || (error == -ENXIO)) { - /* Driver matched, but didn't support device - * or device not found. - * Not an error; keep going. - */ - error = 0; - } else { - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } - return error; - } - /* stop looking, this device is attached */ - return 1; + return driver_probe_device(drv, dev); } /** @@ -114,37 +118,43 @@ static int __device_attach(struct device_driver * drv, void * data) * Walk the list of drivers that the bus has and call * driver_probe_device() for each pair. If a compatible * pair is found, break out and return. + * + * Returns 1 if the device was bound to a driver; 0 otherwise. */ int device_attach(struct device * dev) { + int ret = 0; + + down(&dev->sem); if (dev->driver) { device_bind_driver(dev); - return 1; - } - - return bus_for_each_drv(dev->bus, NULL, dev, __device_attach); + ret = 1; + } else + ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach); + up(&dev->sem); + return ret; } static int __driver_attach(struct device * dev, void * data) { struct device_driver * drv = data; - int error = 0; - - if (!dev->driver) { - error = driver_probe_device(drv, dev); - if (error) { - if (error != -ENODEV) { - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } else - error = 0; - return error; - } - /* stop looking, this driver is attached */ - return 1; - } + + /* + * Lock device and try to bind to it. We drop the error + * here and always return 0, because we need to keep trying + * to bind to devices and some drivers will return an error + * simply if it didn't support the device. + * + * driver_probe_device() will spit a warning if there + * is an error. + */ + + down(&dev->sem); + if (!dev->driver) + driver_probe_device(drv, dev); + up(&dev->sem); + + return 0; } @@ -156,9 +166,6 @@ static int __driver_attach(struct device * dev, void * data) * match the driver with each one. If driver_probe_device() * returns 0 and the @dev->driver is set, we've found a * compatible pair. - * - * Note that we ignore the -ENODEV error from driver_probe_device(), - * since it's perfectly valid for a driver not to bind to any devices. */ void driver_attach(struct device_driver * drv) { @@ -176,19 +183,19 @@ void driver_attach(struct device_driver * drv) */ void device_release_driver(struct device * dev) { - struct device_driver * drv = dev->driver; - - if (!drv) - return; - - sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); - sysfs_remove_link(&dev->kobj, "driver"); - klist_del(&dev->knode_driver); + struct device_driver * drv; down(&dev->sem); - if (drv->remove) - drv->remove(dev); - dev->driver = NULL; + if (dev->driver) { + drv = dev->driver; + sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); + sysfs_remove_link(&dev->kobj, "driver"); + klist_del(&dev->knode_driver); + + if (drv->remove) + drv->remove(dev); + dev->driver = NULL; + } up(&dev->sem); } @@ -208,7 +215,6 @@ void driver_detach(struct device_driver * drv) } -EXPORT_SYMBOL_GPL(driver_probe_device); EXPORT_SYMBOL_GPL(device_bind_driver); EXPORT_SYMBOL_GPL(device_release_driver); EXPORT_SYMBOL_GPL(device_attach); diff --git a/include/linux/device.h b/include/linux/device.h index 4324926..91aac34 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -325,7 +325,6 @@ extern int device_for_each_child(struct device *, void *, * Manual binding of a device to driver. See drivers/base/bus.c * for information on use. */ -extern int driver_probe_device(struct device_driver * drv, struct device * dev); extern void device_bind_driver(struct device * dev); extern void device_release_driver(struct device * dev); extern int device_attach(struct device * dev); |
