Release 4.14 drivers/base/dd.c

/*
 * drivers/base/dd.c - The core device/driver interactions.
 *
 * This file contains the (sometimes tricky) code that controls the
 * interactions between devices and drivers, which primarily includes
 * driver binding and unbinding.
 *
 * All of this code used to exist in drivers/base/bus.c, but was
 * relocated to here in the name of compartmentalization (since it wasn't
 * strictly code just for the 'struct bus_type'.
 *
 * Copyright (c) 2002-5 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2007-2009 Novell Inc.
 *
 * This file is released under the GPLv2
 */

#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/async.h>
#include <linux/pm_runtime.h>
#include <linux/pinctrl/devinfo.h>

#include "base.h"
#include "power/power.h"

/*
 * Deferred Probe infrastructure.
 *
 * Sometimes driver probe order matters, but the kernel doesn't always have
 * dependency information which means some drivers will get probed before a
 * resource it depends on is available.  For example, an SDHCI driver may
 * first need a GPIO line from an i2c GPIO controller before it can be
 * initialized.  If a required resource is not available yet, a driver can
 * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
 *
 * Deferred probe maintains two lists of devices, a pending list and an active
 * list.  A driver returning -EPROBE_DEFER causes the device to be added to the
 * pending list.  A successful driver probe will trigger moving all devices
 * from the pending to the active list so that the workqueue will eventually
 * retry them.
 *
 * The deferred_probe_mutex must be held any time the deferred_probe_*_list
 * of the (struct device*)->p->deferred_probe pointers are manipulated
 */
static DEFINE_MUTEX(deferred_probe_mutex);
static LIST_HEAD(deferred_probe_pending_list);
static LIST_HEAD(deferred_probe_active_list);

static atomic_t deferred_trigger_count = ATOMIC_INIT(0);

static bool initcalls_done;

/*
 * In some cases, like suspend to RAM or hibernation, It might be reasonable
 * to prohibit probing of devices as it could be unsafe.
 * Once defer_all_probes is true all drivers probes will be forcibly deferred.
 */

static bool defer_all_probes;

/*
 * For initcall_debug, show the deferred probes executed in late_initcall
 * processing.
 */


static void deferred_probe_debug(struct device *dev)
{
	ktime_t calltime, delta, rettime;
	unsigned long long duration;

	printk(KERN_DEBUG "deferred probe %s @ %i\n", dev_name(dev),
	       task_pid_nr(current));
	calltime = ktime_get();
	bus_probe_device(dev);
	rettime = ktime_get();
	delta = ktime_sub(rettime, calltime);
	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
	printk(KERN_DEBUG "deferred probe %s returned after %lld usecs\n",
	       dev_name(dev), duration);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Todd Android Poynor
90
100.00%
1
100.00%
Total
90
100.00%
1
100.00%

/*
 * deferred_probe_work_func() - Retry probing devices in the active list.
 */


static void deferred_probe_work_func(struct work_struct *work)
{
	struct device *dev;
	struct device_private *private;
	/*
         * This block processes every device in the deferred 'active' list.
         * Each device is removed from the active list and passed to
         * bus_probe_device() to re-attempt the probe.  The loop continues
         * until every device in the active list is removed and retried.
         *
         * Note: Once the device is removed from the list and the mutex is
         * released, it is possible for the device get freed by another thread
         * and cause a illegal pointer dereference.  This code uses
         * get/put_device() to ensure the device structure cannot disappear
         * from under our feet.
         */
	mutex_lock(&deferred_probe_mutex);
	while (!list_empty(&deferred_probe_active_list)) {
		private = list_first_entry(&deferred_probe_active_list,
					typeof(*dev->p), deferred_probe);
		dev = private->device;
		list_del_init(&private->deferred_probe);

		get_device(dev);

		/*
                 * Drop the mutex while probing each device; the probe path may
                 * manipulate the deferred list
                 */
		mutex_unlock(&deferred_probe_mutex);

		/*
                 * Force the device to the end of the dpm_list since
                 * the PM code assumes that the order we add things to
                 * the list is a good order for suspend but deferred
                 * probe makes that very unsafe.
                 */
		device_pm_lock();
		device_pm_move_last(dev);
		device_pm_unlock();

		dev_dbg(dev, "Retrying from deferred list\n");
		if (initcall_debug && !initcalls_done)
			deferred_probe_debug(dev);
		else
			bus_probe_device(dev);

		mutex_lock(&deferred_probe_mutex);

		put_device(dev);
	}
	mutex_unlock(&deferred_probe_mutex);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Grant C. Likely
96
70.07%
1
20.00%
Greg Kroah-Hartman
16
11.68%
2
40.00%
Todd Android Poynor
13
9.49%
1
20.00%
Mark Brown
12
8.76%
1
20.00%
Total
137
100.00%
5
100.00%

static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);



static void driver_deferred_probe_add(struct device *dev)
{
	mutex_lock(&deferred_probe_mutex);
	if (list_empty(&dev->p->deferred_probe)) {
		dev_dbg(dev, "Added to deferred list\n");
		list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list);
	}
	mutex_unlock(&deferred_probe_mutex);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Grant C. Likely
52
91.23%
1
33.33%
Greg Kroah-Hartman
4
7.02%
1
33.33%
Kuninori Morimoto
1
1.75%
1
33.33%
Total
57
100.00%
3
100.00%



void driver_deferred_probe_del(struct device *dev)
{
	mutex_lock(&deferred_probe_mutex);
	if (!list_empty(&dev->p->deferred_probe)) {
		dev_dbg(dev, "Removed from deferred list\n");
		list_del_init(&dev->p->deferred_probe);
	}
	mutex_unlock(&deferred_probe_mutex);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Grant C. Likely
50
92.59%
1
50.00%
Greg Kroah-Hartman
4
7.41%
1
50.00%
Total
54
100.00%
2
100.00%


static bool driver_deferred_probe_enable = false;
/**
 * driver_deferred_probe_trigger() - Kick off re-probing deferred devices
 *
 * This functions moves all devices from the pending list to the active
 * list and schedules the deferred probe workqueue to process them.  It
 * should be called anytime a driver is successfully bound to a device.
 *
 * Note, there is a race condition in multi-threaded probe. In the case where
 * more than one device is probing at the same time, it is possible for one
 * probe to complete successfully while another is about to defer. If the second
 * depends on the first, then it will get put on the pending list after the
 * trigger event has already occurred and will be stuck there.
 *
 * The atomic 'deferred_trigger_count' is used to determine if a successful
 * trigger has occurred in the midst of probing a driver. If the trigger count
 * changes in the midst of a probe, then deferred processing should be triggered
 * again.
 */


static void driver_deferred_probe_trigger(void)
{
	if (!driver_deferred_probe_enable)
		return;

	/*
         * A successful probe means that all the devices in the pending list
         * should be triggered to be reprobed.  Move all the deferred devices
         * into the active list so they can be retried by the workqueue
         */
	mutex_lock(&deferred_probe_mutex);
	atomic_inc(&deferred_trigger_count);
	list_splice_tail_init(&deferred_probe_pending_list,
			      &deferred_probe_active_list);
	mutex_unlock(&deferred_probe_mutex);

	/*
         * Kick the re-probe thread.  It may already be scheduled, but it is
         * safe to kick it again.
         */
	schedule_work(&deferred_probe_work);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Grant C. Likely
46
93.88%
2
50.00%
Greg Kroah-Hartman
2
4.08%
1
25.00%
Bhaktipriya Shridhar
1
2.04%
1
25.00%
Total
49
100.00%
4
100.00%

/**
 * device_block_probing() - Block/defere device's probes
 *
 *      It will disable probing of devices and defer their probes instead.
 */


void device_block_probing(void)
{
	defer_all_probes = true;
	/* sync with probes to avoid races. */
	wait_for_device_probe();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Grygorii Strashko
15
100.00%
1
100.00%
Total
15
100.00%
1
100.00%

/**
 * device_unblock_probing() - Unblock/enable device's probes
 *
 *      It will restore normal behavior and trigger re-probing of deferred
 * devices.
 */


void device_unblock_probing(void)
{
	defer_all_probes = false;
	driver_deferred_probe_trigger();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Grygorii Strashko
14
100.00%
1
100.00%
Total
14
100.00%
1
100.00%

/**
 * deferred_probe_initcall() - Enable probing of deferred devices
 *
 * We don't want to get in the way when the bulk of drivers are getting probed.
 * Instead, this initcall makes sure that deferred probing is delayed until
 * late_initcall time.
 */


static int deferred_probe_initcall(void)
{
	driver_deferred_probe_enable = true;
	driver_deferred_probe_trigger();
	/* Sort as many dependencies as possible before exiting initcalls */
	flush_work(&deferred_probe_work);
	initcalls_done = true;
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Grant C. Likely
22
75.86%
2
50.00%
Todd Android Poynor
4
13.79%
1
25.00%
Bhaktipriya Shridhar
3
10.34%
1
25.00%
Total
29
100.00%
4
100.00%


late_initcall(deferred_probe_initcall);

/**
 * device_is_bound() - Check if device is bound to a driver
 * @dev: device to check
 *
 * Returns true if passed device has already finished probing successfully
 * against a driver.
 *
 * This function must be called with the device lock held.
 */


bool device_is_bound(struct device *dev)
{
	return dev->p && klist_node_attached(&dev->p->knode_driver);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Daniel Ritz
7
28.00%
1
20.00%
Patrick Mochel
7
28.00%
1
20.00%
Tomeu Vizoso
5
20.00%
1
20.00%
Rafael J. Wysocki
4
16.00%
1
20.00%
Greg Kroah-Hartman
2
8.00%
1
20.00%
Total
25
100.00%
5
100.00%



static void driver_bound(struct device *dev)
{
	if (device_is_bound(dev)) {
		printk(KERN_WARNING "%s: device %s already bound\n",
			__func__, kobject_name(&dev->kobj));
		return;
	}

	pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
		 __func__, dev_name(dev));

	klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
	device_links_driver_bound(dev);

	device_pm_check_callbacks(dev);

	/*
         * Make sure the device is no longer in one of the deferred lists and
         * kick off retrying all pending devices
         */
	driver_deferred_probe_del(dev);
	driver_deferred_probe_trigger();

	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_BOUND_DRIVER, dev);

	kobject_uevent(&dev->kobj, KOBJ_BIND);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tomeu Vizoso
21
16.80%
2
12.50%
Benjamin Herrenschmidt
20
16.00%
1
6.25%
Stefani Seibold
19
15.20%
1
6.25%
Andrew Morton
17
13.60%
1
6.25%
Patrick Mochel
10
8.00%
1
6.25%
Dmitry Torokhov
10
8.00%
1
6.25%
Grant C. Likely
8
6.40%
1
6.25%
Frank Rowand
7
5.60%
1
6.25%
Rafael J. Wysocki
5
4.00%
1
6.25%
Greg Kroah-Hartman
4
3.20%
3
18.75%
Kay Sievers
2
1.60%
1
6.25%
Daniel Ritz
1
0.80%
1
6.25%
Harvey Harrison
1
0.80%
1
6.25%
Total
125
100.00%
16
100.00%



static int driver_sysfs_add(struct device *dev)
{
	int ret;

	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_BIND_DRIVER, dev);

	ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
			  kobject_name(&dev->kobj));
	if (ret == 0) {
		ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
					"driver");
		if (ret)
			sysfs_remove_link(&dev->driver->p->kobj,
					kobject_name(&dev->kobj));
	}
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
41
34.45%
1
20.00%
Andrew Morton
37
31.09%
1
20.00%
Magnus Damm
22
18.49%
1
20.00%
Kay Sievers
13
10.92%
1
20.00%
Greg Kroah-Hartman
6
5.04%
1
20.00%
Total
119
100.00%
5
100.00%



static void driver_sysfs_remove(struct device *dev)
{
	struct device_driver *drv = dev->driver;

	if (drv) {
		sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
		sysfs_remove_link(&dev->kobj, "driver");
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kay Sievers
52
96.30%
1
50.00%
Greg Kroah-Hartman
2
3.70%
1
50.00%
Total
54
100.00%
2
100.00%

/**
 * device_bind_driver - bind a driver to one device.
 * @dev: device.
 *
 * Allow manual attachment of a driver to a device.
 * Caller must have already set @dev->driver.
 *
 * Note that this does not modify the bus reference count
 * 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 the device lock held.
 */


int device_bind_driver(struct device *dev)
{
	int ret;

	ret = driver_sysfs_add(dev);
	if (!ret)
		driver_bound(dev);
	else if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andy Shevchenko
23
41.07%
1
33.33%
Kay Sievers
18
32.14%
1
33.33%
Cornelia Huck
15
26.79%
1
33.33%
Total
56
100.00%
3
100.00%


EXPORT_SYMBOL_GPL(device_bind_driver);


static atomic_t probe_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);



static int really_probe(struct device *dev, struct device_driver *drv)
{
	int ret = -EPROBE_DEFER;
	int local_trigger_count = atomic_read(&deferred_trigger_count);
	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
			   !drv->suppress_bind_attrs;

	if (defer_all_probes) {
		/*
                 * Value of defer_all_probes can be set only by
                 * device_defer_all_probes_enable() which, in turn, will call
                 * wait_for_device_probe() right after that to avoid any races.
                 */
		dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
		driver_deferred_probe_add(dev);
		return ret;
	}

	ret = device_links_check_suppliers(dev);
	if (ret)
		return ret;

	atomic_inc(&probe_count);
	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
		 drv->bus->name, __func__, drv->name, dev_name(dev));
	WARN_ON(!list_empty(&dev->devres_head));

re_probe:
	dev->driver = drv;

	/* If using pinctrl, bind pins now before probing */
	ret = pinctrl_bind_pins(dev);
	if (ret)
		goto pinctrl_bind_failed;

	ret = dma_configure(dev);
	if (ret)
		goto dma_failed;

	if (driver_sysfs_add(dev)) {
		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
			__func__, dev_name(dev));
		goto probe_failed;
	}

	if (dev->pm_domain && dev->pm_domain->activate) {
		ret = dev->pm_domain->activate(dev);
		if (ret)
			goto probe_failed;
	}

	/*
         * Ensure devices are listed in devices_kset in correct order
         * It's important to move Dev to the end of devices_kset before
         * calling .probe, because it could be recursive and parent Dev
         * should always go first
         */
	devices_kset_move_last(dev);

	if (dev->bus->probe) {
		ret = dev->bus->probe(dev);
		if (ret)
			goto probe_failed;
	} else if (drv->probe) {
		ret = drv->probe(dev);
		if (ret)
			goto probe_failed;
	}

	if (test_remove) {
		test_remove = false;

		if (dev->bus->remove)
			dev->bus->remove(dev);
		else if (drv->remove)
			drv->remove(dev);

		devres_release_all(dev);
		driver_sysfs_remove(dev);
		dev->driver = NULL;
		dev_set_drvdata(dev, NULL);
		if (dev->pm_domain && dev->pm_domain->dismiss)
			dev->pm_domain->dismiss(dev);
		pm_runtime_reinit(dev);

		goto re_probe;
	}

	pinctrl_init_done(dev);

	if (dev->pm_domain && dev->pm_domain->sync)
		dev->pm_domain->sync(dev);

	driver_bound(dev);
	ret = 1;
	pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
		 drv->bus->name, __func__, dev_name(dev), drv->name);
	goto done;

probe_failed:
	dma_deconfigure(dev);
dma_failed:
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
pinctrl_bind_failed:
	device_links_no_driver(dev);
	devres_release_all(dev);
	driver_sysfs_remove(dev);
	dev->driver = NULL;
	dev_set_drvdata(dev, NULL);
	if (dev->pm_domain && dev->pm_domain->dismiss)
		dev->pm_domain->dismiss(dev);
	pm_runtime_reinit(dev);

	switch (ret) {
	case -EPROBE_DEFER:
		/* Driver requested deferred probing */
		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
		driver_deferred_probe_add(dev);
		/* Did a trigger occur while probing? Need to re-trigger if yes */
		if (local_trigger_count != atomic_read(&deferred_trigger_count))
			driver_deferred_probe_trigger();
		break;
	case -ENODEV:
	case -ENXIO:
		pr_debug("%s: probe of %s rejects match %d\n",
			 drv->name, dev_name(dev), ret);
		break;
	default:
		/* driver matched but the probe failed */
		printk(KERN_WARNING
		       "%s: probe of %s failed with error %d\n",
		       drv->name, dev_name(dev), ret);
	}
	/*
         * Ignore errors returned by ->probe so that the next driver can try
         * its luck.
         */
	ret = 0;
done:
	atomic_dec(&probe_count);
	wake_up(&probe_waitqueue);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rob Herring
108
17.28%
2
6.90%
Patrick Mochel
101
16.16%
2
6.90%
Rafael J. Wysocki
91
14.56%
2
6.90%
Kay Sievers
45
7.20%
2
6.90%
Grant C. Likely
41
6.56%
2
6.90%
Grygorii Strashko
34
5.44%
2
6.90%
Greg Kroah-Hartman
30
4.80%
2
6.90%
Russell King
28
4.48%
1
3.45%
Andy Shevchenko
25
4.00%
1
3.45%
R Sricharan
21
3.36%
1
3.45%
Sergei Shtylyov
18
2.88%
1
3.45%
Tejun Heo
17
2.72%
1
3.45%
Wolfram Sang
15
2.40%
1
3.45%
Linus Walleij
14
2.24%
1
3.45%
Cornelia Huck
10
1.60%
2
6.90%
Hans de Goede
7
1.12%
1
3.45%
Andrew Morton
6
0.96%
1
3.45%
Douglas Anderson
5
0.80%
1
3.45%
Ulf Hansson
5
0.80%
1
3.45%
Harvey Harrison
3
0.48%
1
3.45%
Mark Brown
1
0.16%
1
3.45%
Total
625
100.00%
29
100.00%

/**
 * 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", __func__,
		 atomic_read(&probe_count));
	if (atomic_read(&probe_count))
		return -EBUSY;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Greg Kroah-Hartman
34
97.14%
1
50.00%
Harvey Harrison
1
2.86%
1
50.00%
Total
35
100.00%
2
100.00%

/**
 * wait_for_device_probe
 * Wait for device probing to be completed.
 */


void wait_for_device_probe(void)
{
	/* wait for the deferred probe workqueue to finish */
	flush_work(&deferred_probe_work);

	/* wait for the known devices to complete their probing */
	wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
	async_synchronize_full();
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Arjan van de Ven
13
41.94%
1
25.00%
Lei Ming
11
35.48%
1
25.00%
Grygorii Strashko
4
12.90%
1
25.00%
Bhaktipriya Shridhar
3
9.68%
1
25.00%
Total
31
100.00%
4
100.00%


EXPORT_SYMBOL_GPL(wait_for_device_probe);

/**
 * 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
 *
 * This function returns -ENODEV if the device is not registered,
 * 1 if the device is bound successfully and 0 otherwise.
 *
 * This function must be called with @dev lock held.  When called for a
 * USB interface, @dev->parent lock must be held as well.
 *
 * If the device has a parent, runtime-resume the parent before driver probing.
 */


int driver_probe_device(struct device_driver *drv, struct device *dev)
{
	int ret = 0;

	if (!device_is_registered(dev))
		return -ENODEV;

	pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
		 drv->bus->name, __func__, dev_name(dev), drv->name);

	pm_runtime_get_suppliers(dev);
	if (dev->parent)
		pm_runtime_get_sync(dev->parent);

	pm_runtime_barrier(dev);
	ret = really_probe(dev, drv);
	pm_request_idle(dev);

	if (dev->parent)
		pm_runtime_put(dev->parent);

	pm_runtime_put_suppliers(dev);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Greg Kroah-Hartman
46
41.07%
3
21.43%
Rafael J. Wysocki
45
40.18%
3
21.43%
Alan Stern
10
8.93%
1
7.14%
Cornelia Huck
3
2.68%
1
7.14%
Kay Sievers
3
2.68%
1
7.14%
Patrick Mochel
2
1.79%
2
14.29%
Duncan Sands
1
0.89%
1
7.14%
Harvey Harrison
1
0.89%
1
7.14%
Ulf Hansson
1
0.89%
1
7.14%
Total
112
100.00%
14
100.00%



bool driver_allows_async_probing(struct device_driver *drv)
{
	switch (drv->probe_type) {
	case PROBE_PREFER_ASYNCHRONOUS:
		return true;

	case PROBE_FORCE_SYNCHRONOUS:
		return false;

	default:
		if (module_requested_async_probing(drv->owner))
			return true;

		return false;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Luis R. Rodriguez
29
63.04%
2
50.00%
Dmitry Torokhov
17
36.96%
2
50.00%
Total
46
100.00%
4
100.00%


struct device_attach_data {
	
struct device *dev;

	/*
         * Indicates whether we are are considering asynchronous probing or
         * not. Only initial binding after device or driver registration
         * (including deferral processing) may be done asynchronously, the
         * rest is always synchronous, as we expect it is being done by
         * request from userspace.
         */
	
bool check_async;

	/*
         * Indicates if we are binding synchronous or asynchronous drivers.
         * When asynchronous probing is enabled we'll execute 2 passes
         * over drivers: first pass doing synchronous probing and second
         * doing asynchronous probing (if synchronous did not succeed -
         * most likely because there was no driver requiring synchronous
         * probing - and we found asynchronous driver during first pass).
         * The 2 passes are done because we can't shoot asynchronous
         * probe for given device and driver from bus_for_each_drv() since
         * driver pointer is not guaranteed to stay valid once
         * bus_for_each_drv() iterates to the next driver on the bus.
         */
	
bool want_async;

	/*
         * We'll set have_async to 'true' if, while scanning for matching
         * driver, we'll encounter one that requests asynchronous probing.
         */
	
bool have_async;
};



static int __device_attach_driver(struct device_driver *drv, void *_data)
{
	struct device_attach_data *data = _data;
	struct device *dev = data->dev;
	bool async_allowed;
	int ret;

	/*
         * Check if device has already been claimed. This may
         * happen with driver loading, device discovery/registration,
         * and deferred probe processing happens all at once with
         * multiple threads.
         */
	if (dev->driver)
		return -EBUSY;

	ret = driver_match_device(drv, dev);
	if (ret == 0) {
		/* no match */
		return 0;
	} else if (ret == -EPROBE_DEFER) {
		dev_dbg(dev, "Device match requests probe deferral\n");
		driver_deferred_probe_add(dev);
	} else if (ret < 0) {
		dev_dbg(dev, "Bus failed to match device: %d", ret);
		return ret;
	} /* ret > 0 means positive match */

	async_allowed = driver_allows_async_probing(drv);

	if (async_allowed)
		data->have_async = true;

	if (data->check_async && async_allowed != data->want_async)
		return 0;

	return driver_probe_device(drv, dev);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tomeu Vizoso
58
37.91%
1
16.67%
Dmitry Torokhov
57
37.25%
1
16.67%
Patrick Mochel
27
17.65%
2
33.33%
Lei Ming
10
6.54%
1
16.67%
Greg Kroah-Hartman
1
0.65%
1
16.67%
Total
153
100.00%
6
100.00%



static void __device_attach_async_helper(void *_dev, async_cookie_t cookie)
{
	struct device *dev = _dev;
	struct device_attach_data data = {
		.dev		= dev,
		.check_async	= true,
		.want_async	= true,
        };

	device_lock(dev);

	if (dev->parent)
		pm_runtime_get_sync(dev->parent);

	bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
	dev_dbg(dev, "async probe completed\n");

	pm_request_idle(dev);

	if (dev->parent)
		pm_runtime_put(dev->parent);

	device_unlock(dev);

	put_device(dev);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
82
75.93%
1
50.00%
Rafael J. Wysocki
26
24.07%
1
50.00%
Total
108
100.00%
2
100.00%



static int __device_attach(struct device *dev, bool allow_async)
{
	int ret = 0;

	device_lock(dev);
	if (dev->driver) {
		if (device_is_bound(dev)) {
			ret = 1;
			goto out_unlock;
		}
		ret = device_bind_driver(dev);
		if (ret == 0)
			ret = 1;
		else {
			dev->driver = NULL;
			ret = 0;
		}
	} else {
		struct device_attach_data data = {
			.dev = dev,
			.check_async = allow_async,
			.want_async = false,
                };

		if (dev->parent)
			pm_runtime_get_sync(dev->parent);

		ret = bus_for_each_drv(dev->bus, NULL, &data,
					__device_attach_driver);
		if (!ret && allow_async && data.have_async) {
			/*
                         * If we could not find appropriate driver
                         * synchronously and we are allowed to do
                         * async probes and there are drivers that
                         * want to probe asynchronously, we'll
                         * try them.
                         */
			dev_dbg(dev, "scheduling asynchronous probe\n");
			get_device(dev);
			async_schedule(__device_attach_async_helper, dev);
		} else {
			pm_request_idle(dev);
		}

		if (dev->parent)
			pm_runtime_put(dev->parent);
	}
out_unlock:
	device_unlock(dev);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
64
32.82%
2
14.29%
Patrick Mochel
57
29.23%
3
21.43%
Rafael J. Wysocki
30
15.38%
2
14.29%
Sebastian Ott
17
8.72%
1
7.14%
Cornelia Huck
15
7.69%
2
14.29%
Andrew Morton
8
4.10%
1
7.14%
Greg Kroah-Hartman
2
1.03%
1
7.14%
Ulf Hansson
1
0.51%
1
7.14%
Tomeu Vizoso
1
0.51%
1
7.14%
Total
195
100.00%
14
100.00%

/**
 * device_attach - try to attach device to a driver.
 * @dev: device.
 *
 * 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 if no matching driver was found;
 * -ENODEV if the device is not registered.
 *
 * When called for a USB interface, @dev->parent lock must be held.
 */


int device_attach(struct device *dev)
{
	return __device_attach(dev, false);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
18
100.00%
1
100.00%
Total
18
100.00%
1
100.00%


EXPORT_SYMBOL_GPL(device_attach);



void device_initial_probe(struct device *dev)
{
	__device_attach(dev, true);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
17
100.00%
1
100.00%
Total
17
100.00%
1
100.00%



static int __driver_attach(struct device *dev, void *data)
{
	struct device_driver *drv = data;
	int ret;

	/*
         * 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.
         */

	ret = driver_match_device(drv, dev);
	if (ret == 0) {
		/* no match */
		return 0;
	} else if (ret == -EPROBE_DEFER) {
		dev_dbg(dev, "Device match requests probe deferral\n");
		driver_deferred_probe_add(dev);
	} else if (ret < 0) {
		dev_dbg(dev, "Bus failed to match device: %d", ret);
		return ret;
	} /* ret > 0 means positive match */

	if (dev->parent)	/* Needed for USB */
		device_lock(dev->parent);
	device_lock(dev);
	if (!dev->driver)
		driver_probe_device(drv, dev);
	device_unlock(dev);
	if (dev->parent)
		device_unlock(dev->parent);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tomeu Vizoso
58
40.00%
1
12.50%
Patrick Mochel
48
33.10%
3
37.50%
Alan Stern
23
15.86%
1
12.50%
Arjan van de Ven
9
6.21%
1
12.50%
Greg Kroah-Hartman
4
2.76%
1
12.50%
Lei Ming
3
2.07%
1
12.50%
Total
145
100.00%
8
100.00%

/**
 * driver_attach - try to bind driver to devices.
 * @drv: driver.
 *
 * Walk the list of devices that the bus has on it and try to
 * match the driver with each one.  If driver_probe_device()
 * returns 0 and the @dev->driver is set, we've found a
 * compatible pair.
 */


int driver_attach(struct device_driver *drv)
{
	return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
21
87.50%
2
66.67%
Andrew Morton
3
12.50%
1
33.33%
Total
24
100.00%
3
100.00%


EXPORT_SYMBOL_GPL(driver_attach);

/*
 * __device_release_driver() must be called with @dev lock held.
 * When called for a USB interface, @dev->parent lock must be held as well.
 */


static void __device_release_driver(struct device *dev, struct device *parent)
{
	struct device_driver *drv;

	drv = dev->driver;
	if (drv) {
		if (driver_allows_async_probing(drv))
			async_synchronize_full();

		while (device_links_busy(dev)) {
			device_unlock(dev);
			if (parent)
				device_unlock(parent);

			device_links_unbind_consumers(dev);
			if (parent)
				device_lock(parent);

			device_lock(dev);
			/*
                         * A concurrent invocation of the same function might
                         * have released the driver successfully while this one
                         * was waiting, so check for that.
                         */
			if (dev->driver != drv)
				return;
		}

		pm_runtime_get_sync(dev);
		pm_runtime_clean_up_links(dev);

		driver_sysfs_remove(dev);

		if (dev->bus)
			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
						     BUS_NOTIFY_UNBIND_DRIVER,
						     dev);

		pm_runtime_put_sync(dev);

		if (dev->bus && dev->bus->remove)
			dev->bus->remove(dev);
		else if (drv->remove)
			drv->remove(dev);

		device_links_driver_cleanup(dev);
		dma_deconfigure(dev);

		devres_release_all(dev);
		dev->driver = NULL;
		dev_set_drvdata(dev, NULL);
		if (dev->pm_domain && dev->pm_domain->dismiss)
			dev->pm_domain->dismiss(dev);
		pm_runtime_reinit(dev);

		klist_remove(&dev->p->knode_driver);
		device_pm_check_callbacks(dev);
		if (dev->bus)
			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
						     BUS_NOTIFY_UNBOUND_DRIVER,
						     dev);

		kobject_uevent(&dev->kobj, KOBJ_UNBIND);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rafael J. Wysocki
98
35.90%
6
25.00%
Patrick Mochel
47
17.22%
2
8.33%
Joerg Roedel
22
8.06%
1
4.17%
Benjamin Herrenschmidt
20
7.33%
1
4.17%
Dmitry Torokhov
20
7.33%
2
8.33%
Russell King
18
6.59%
1
4.17%
Alan Stern
16
5.86%
3
12.50%
Hans de Goede
7
2.56%
1
4.17%
Tejun Heo
5
1.83%
1
4.17%
R Sricharan
5
1.83%
1
4.17%
Tomeu Vizoso
5
1.83%
1
4.17%
Ulf Hansson
5
1.83%
1
4.17%
Greg Kroah-Hartman
4
1.47%
2
8.33%
Kay Sievers
1
0.37%
1
4.17%
Total
273
100.00%
24
100.00%



void device_release_driver_internal(struct device *dev,
				    struct device_driver *drv,
				    struct device *parent)
{
	if (parent)
		device_lock(parent);

	device_lock(dev);
	if (!drv || drv == dev->driver)
		__device_release_driver(dev, parent);

	device_unlock(dev);
	if (parent)
		device_unlock(parent);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rafael J. Wysocki
43
65.15%
2
40.00%
Patrick Mochel
11
16.67%
1
20.00%
Alan Stern
10
15.15%
1
20.00%
Greg Kroah-Hartman
2
3.03%
1
20.00%
Total
66
100.00%
5
100.00%

/**
 * device_release_driver - manually detach device from driver.
 * @dev: device.
 *
 * Manually detach device from driver.
 * When called for a USB interface, @dev->parent lock must be held.
 *
 * If this function is to be called with @dev->parent lock held, ensure that
 * the device's consumers are unbound in advance or that their locks can be
 * acquired under the @dev->parent lock.
 */


void device_release_driver(struct device *dev)
{
	/*
         * If anyone calls device_release_driver() recursively from
         * within their ->remove callback for the same device, they
         * will deadlock right here.
         */
	device_release_driver_internal(dev, NULL, NULL);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Rafael J. Wysocki
19
95.00%
1
50.00%
Patrick Mochel
1
5.00%
1
50.00%
Total
20
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(device_release_driver);

/**
 * driver_detach - detach driver from all devices it controls.
 * @drv: driver.
 */


void driver_detach(struct device_driver *drv)
{
	struct device_private *dev_prv;
	struct device *dev;

	for (;;) {
		spin_lock(&drv->p->klist_devices.k_lock);
		if (list_empty(&drv->p->klist_devices.k_list)) {
			spin_unlock(&drv->p->klist_devices.k_lock);
			break;
		}
		dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
				     struct device_private,
				     knode_driver.n_node);
		dev = dev_prv->device;
		get_device(dev);
		spin_unlock(&drv->p->klist_devices.k_lock);
		device_release_driver_internal(dev, drv, dev->parent);
		put_device(dev);
	}
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Alan Stern
89
68.99%
3
37.50%
Greg Kroah-Hartman
23
17.83%
2
25.00%
Patrick Mochel
14
10.85%
2
25.00%
Rafael J. Wysocki
3
2.33%
1
12.50%
Total
129
100.00%
8
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
400
13.37%
4
4.65%
Rafael J. Wysocki
369
12.33%
9
10.47%
Grant C. Likely
362
12.10%
3
3.49%
Dmitry Torokhov
308
10.29%
4
4.65%
Greg Kroah-Hartman
224
7.49%
11
12.79%
Tomeu Vizoso
149
4.98%
3
3.49%
Alan Stern
148
4.95%
6
6.98%
Kay Sievers
134
4.48%
2
2.33%
Todd Android Poynor
115
3.84%
1
1.16%
Rob Herring
108
3.61%
2
2.33%
Andrew Morton
80
2.67%
2
2.33%
Grygorii Strashko
74
2.47%
2
2.33%
Andy Shevchenko
48
1.60%
1
1.16%
Russell King
46
1.54%
1
1.16%
Cornelia Huck
43
1.44%
4
4.65%
Benjamin Herrenschmidt
40
1.34%
1
1.16%
Arjan van de Ven
33
1.10%
3
3.49%
R Sricharan
29
0.97%
1
1.16%
Luis R. Rodriguez
29
0.97%
2
2.33%
Lei Ming
25
0.84%
2
2.33%
Magnus Damm
22
0.74%
1
1.16%
Joerg Roedel
22
0.74%
1
1.16%
Tejun Heo
22
0.74%
1
1.16%
Stefani Seibold
19
0.64%
1
1.16%
Sergei Shtylyov
18
0.60%
1
1.16%
Sebastian Ott
17
0.57%
1
1.16%
Linus Walleij
17
0.57%
1
1.16%
Wolfram Sang
15
0.50%
1
1.16%
Hans de Goede
14
0.47%
1
1.16%
Mark Brown
13
0.43%
2
2.33%
Ulf Hansson
12
0.40%
2
2.33%
Daniel Ritz
8
0.27%
1
1.16%
Bhaktipriya Shridhar
7
0.23%
1
1.16%
Frank Rowand
7
0.23%
1
1.16%
Harvey Harrison
6
0.20%
1
1.16%
Douglas Anderson
5
0.17%
1
1.16%
Thierry Reding
1
0.03%
1
1.16%
Shailendra Verma
1
0.03%
1
1.16%
Kuninori Morimoto
1
0.03%
1
1.16%
Duncan Sands
1
0.03%
1
1.16%
Total
2992
100.00%
86
100.00%
Directory: drivers/base

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.