diff options
| -rw-r--r-- | drivers/base/dd.c | 108 | ||||
| -rw-r--r-- | include/linux/device.h | 3 | ||||
| -rw-r--r-- | init/do_mounts.c | 5 |
3 files changed, 89 insertions, 27 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 9f6f11c..319a73b 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -17,6 +17,7 @@ #include <linux/device.h> #include <linux/module.h> +#include <linux/kthread.h> #include "base.h" #include "power/power.h" @@ -63,44 +64,35 @@ int device_bind_driver(struct device *dev) return ret; } -/** - * driver_probe_device - attempt to bind device & driver. - * @drv: driver. - * @dev: device. - * - * First, we call the bus's match function, if one present, which - * should compare the device IDs the driver supports with the - * device IDs of the device. Note we don't do this ourselves - * because we don't know the format of the ID structures, nor what - * is to be considered a match and what is not. - * - * 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. When called - * for a USB interface, @dev->parent->sem must be held as well. - */ -int driver_probe_device(struct device_driver * drv, struct device * dev) +struct stupid_thread_structure { + struct device_driver *drv; + struct device *dev; +}; + +static atomic_t probe_count = ATOMIC_INIT(0); +static int really_probe(void *void_data) { + struct stupid_thread_structure *data = void_data; + struct device_driver *drv = data->drv; + struct device *dev = data->dev; int ret = 0; - if (drv->bus->match && !drv->bus->match(dev, drv)) - goto Done; + atomic_inc(&probe_count); + pr_debug("%s: Probing driver %s with device %s\n", + drv->bus->name, drv->name, dev->bus_id); - pr_debug("%s: Matched Device %s with Driver %s\n", - drv->bus->name, dev->bus_id, drv->name); dev->driver = drv; if (dev->bus->probe) { ret = dev->bus->probe(dev); if (ret) { dev->driver = NULL; - goto ProbeFailed; + goto probe_failed; } } else if (drv->probe) { ret = drv->probe(dev); if (ret) { dev->driver = NULL; - goto ProbeFailed; + goto probe_failed; } } if (device_bind_driver(dev)) { @@ -111,9 +103,9 @@ int driver_probe_device(struct device_driver * drv, struct device * dev) ret = 1; pr_debug("%s: Bound Device %s to Driver %s\n", drv->bus->name, dev->bus_id, drv->name); - goto Done; + goto done; - ProbeFailed: +probe_failed: if (ret == -ENODEV || ret == -ENXIO) { /* Driver matched, but didn't support device * or device not found. @@ -126,7 +118,69 @@ int driver_probe_device(struct device_driver * drv, struct device * dev) "%s: probe of %s failed with error %d\n", drv->name, dev->bus_id, ret); } - Done: +done: + kfree(data); + atomic_dec(&probe_count); + return ret; +} + +/** + * driver_probe_done + * Determine if the probe sequence is finished or not. + * + * Should somehow figure out how to use a semaphore, not an atomic variable... + */ +int driver_probe_done(void) +{ + pr_debug("%s: probe_count = %d\n", __FUNCTION__, + atomic_read(&probe_count)); + if (atomic_read(&probe_count)) + return -EBUSY; + return 0; +} + +/** + * driver_probe_device - attempt to bind device & driver together + * @drv: driver to bind a device to + * @dev: device to try to bind to the driver + * + * First, we call the bus's match function, if one present, which should + * compare the device IDs the driver supports with the device IDs of the + * device. Note we don't do this ourselves because we don't know the + * format of the ID structures, nor what is to be considered a match and + * what is not. + * + * 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. When called for a + * USB interface, @dev->parent->sem must be held as well. + */ +int driver_probe_device(struct device_driver * drv, struct device * dev) +{ + struct stupid_thread_structure *data; + struct task_struct *probe_task; + int ret = 0; + + if (drv->bus->match && !drv->bus->match(dev, drv)) + goto done; + + pr_debug("%s: Matched Device %s with Driver %s\n", + drv->bus->name, dev->bus_id, drv->name); + + data = kmalloc(sizeof(*data), GFP_KERNEL); + data->drv = drv; + data->dev = dev; + + if (drv->multithread_probe) { + probe_task = kthread_run(really_probe, data, + "probe-%s", dev->bus_id); + if (IS_ERR(probe_task)) + ret = PTR_ERR(probe_task); + } else + ret = really_probe(data); + +done: return ret; } diff --git a/include/linux/device.h b/include/linux/device.h index b3da9a8..74246ef 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -106,6 +106,8 @@ struct device_driver { void (*shutdown) (struct device * dev); int (*suspend) (struct device * dev, pm_message_t state); int (*resume) (struct device * dev); + + unsigned int multithread_probe:1; }; @@ -115,6 +117,7 @@ extern void driver_unregister(struct device_driver * drv); extern struct device_driver * get_driver(struct device_driver * drv); extern void put_driver(struct device_driver * drv); extern struct device_driver *driver_find(const char *name, struct bus_type *bus); +extern int driver_probe_done(void); /* driverfs interface for exporting driver attributes */ diff --git a/init/do_mounts.c b/init/do_mounts.c index 94aeec7..b290aad 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -8,6 +8,7 @@ #include <linux/security.h> #include <linux/delay.h> #include <linux/mount.h> +#include <linux/device.h> #include <linux/nfs_fs.h> #include <linux/nfs_fs_sb.h> @@ -403,6 +404,10 @@ void __init prepare_namespace(void) ssleep(root_delay); } + /* wait for the known devices to complete their probing */ + while (driver_probe_done() != 0) + msleep(100); + md_run_setup(); if (saved_root_name[0]) { |
