Commit 50ad1c21 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'driver-core-5.8-rc6' of... 

Merge tag 'driver-core-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into master

Pull driver core fixes from Greg KH:
 "Here are 3 driver core fixes for 5.8-rc6.

  They resolve some issues found with the deferred probe code for some
  types of devices on some embedded systems. They have been tested a
  bunch and have been in linux-next for a while with no reported issues"

* tag 'driver-core-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Avoid deferred probe due to fw_devlink_pause/resume()
  driver core: Rename dev_links_info.defer_sync to defer_hook
  driver core: Don't do deferred probe in parallel with kernel_init thread
parents 6a058f0b 2451e746

drivers/base/base.h

+0 −1
Original line number Diff line number Diff line
@@ -153,7 +153,6 @@ extern char *make_class_name(const char *name, struct kobject *kobj); 
extern int devres_release_all(struct device *dev);

extern void device_block_probing(void);

extern void device_unblock_probing(void);

extern void driver_deferred_probe_force_trigger(void);



/* /sys/devices directory */

extern struct kset *devices_kset;

drivers/base/core.c

+32 −12
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ static DEFINE_MUTEX(wfs_lock); 
static LIST_HEAD(deferred_sync);

static unsigned int defer_sync_state_count = 1;

static unsigned int defer_fw_devlink_count;

static LIST_HEAD(deferred_fw_devlink);

static DEFINE_MUTEX(defer_fw_devlink_lock);

static bool fw_devlink_is_permissive(void);
@@ -754,11 +755,11 @@ static void __device_links_queue_sync_state(struct device *dev, 
	 */

	dev->state_synced = true;



	if (WARN_ON(!list_empty(&dev->links.defer_sync)))

	if (WARN_ON(!list_empty(&dev->links.defer_hook)))

		return;



	get_device(dev);

	list_add_tail(&dev->links.defer_sync, list);

	list_add_tail(&dev->links.defer_hook, list);

}



/**
@@ -776,8 +777,8 @@ static void device_links_flush_sync_list(struct list_head *list, 
{

	struct device *dev, *tmp;



	list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {

		list_del_init(&dev->links.defer_sync);

	list_for_each_entry_safe(dev, tmp, list, links.defer_hook) {

		list_del_init(&dev->links.defer_hook);



		if (dev != dont_lock_dev)

			device_lock(dev);
@@ -815,12 +816,12 @@ void device_links_supplier_sync_state_resume(void) 
	if (defer_sync_state_count)

		goto out;



	list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) {

	list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_hook) {

		/*

		 * Delete from deferred_sync list before queuing it to

		 * sync_list because defer_sync is used for both lists.

		 * sync_list because defer_hook is used for both lists.

		 */

		list_del_init(&dev->links.defer_sync);

		list_del_init(&dev->links.defer_hook);

		__device_links_queue_sync_state(dev, &sync_list);

	}

out:
@@ -838,8 +839,8 @@ late_initcall(sync_state_resume_initcall); 


static void __device_links_supplier_defer_sync(struct device *sup)

{

	if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))

		list_add_tail(&sup->links.defer_sync, &deferred_sync);

	if (list_empty(&sup->links.defer_hook) && dev_has_sync_state(sup))

		list_add_tail(&sup->links.defer_hook, &deferred_sync);

}



static void device_link_drop_managed(struct device_link *link)
@@ -1052,7 +1053,7 @@ void device_links_driver_cleanup(struct device *dev) 
		WRITE_ONCE(link->status, DL_STATE_DORMANT);

	}



	list_del_init(&dev->links.defer_sync);

	list_del_init(&dev->links.defer_hook);

	__device_links_no_driver(dev);



	device_links_write_unlock();
@@ -1244,6 +1245,12 @@ static void fw_devlink_link_device(struct device *dev) 
			fw_ret = -EAGAIN;

	} else {

		fw_ret = -ENODEV;

		/*

		 * defer_hook is not used to add device to deferred_sync list

		 * until device is bound. Since deferred fw devlink also blocks

		 * probing, same list hook can be used for deferred_fw_devlink.

		 */

		list_add_tail(&dev->links.defer_hook, &deferred_fw_devlink);

	}



	if (fw_ret == -ENODEV)
@@ -1312,6 +1319,9 @@ void fw_devlink_pause(void) 
 */

void fw_devlink_resume(void)

{

	struct device *dev, *tmp;

	LIST_HEAD(probe_list);



	mutex_lock(&defer_fw_devlink_lock);

	if (!defer_fw_devlink_count) {

		WARN(true, "Unmatched fw_devlink pause/resume!");
@@ -1323,9 +1333,19 @@ void fw_devlink_resume(void) 
		goto out;



	device_link_add_missing_supplier_links();

	driver_deferred_probe_force_trigger();

	list_splice_tail_init(&deferred_fw_devlink, &probe_list);

out:

	mutex_unlock(&defer_fw_devlink_lock);



	/*

	 * bus_probe_device() can cause new devices to get added and they'll

	 * try to grab defer_fw_devlink_lock. So, this needs to be done outside

	 * the defer_fw_devlink_lock.

	 */

	list_for_each_entry_safe(dev, tmp, &probe_list, links.defer_hook) {

		list_del_init(&dev->links.defer_hook);

		bus_probe_device(dev);

	}

}

/* Device links support end. */
@@ -2172,7 +2192,7 @@ void device_initialize(struct device *dev) 
	INIT_LIST_HEAD(&dev->links.consumers);

	INIT_LIST_HEAD(&dev->links.suppliers);

	INIT_LIST_HEAD(&dev->links.needs_suppliers);

	INIT_LIST_HEAD(&dev->links.defer_sync);

	INIT_LIST_HEAD(&dev->links.defer_hook);

	dev->links.status = DL_DEV_NO_DRIVER;

}

EXPORT_SYMBOL_GPL(device_initialize);

drivers/base/dd.c

+0 −5
Original line number Diff line number Diff line
@@ -164,11 +164,6 @@ static void driver_deferred_probe_trigger(void) 
	if (!driver_deferred_probe_enable)

		return;



	driver_deferred_probe_force_trigger();

}



void driver_deferred_probe_force_trigger(void)

{

	/*

	 * A successful probe means that all the devices in the pending list

	 * should be triggered to be reprobed.  Move all the deferred devices

include/linux/device.h

+3 −2
Original line number Diff line number Diff line
@@ -433,7 +433,8 @@ enum dl_dev_state { 
 * @suppliers: List of links to supplier devices.

 * @consumers: List of links to consumer devices.

 * @needs_suppliers: Hook to global list of devices waiting for suppliers.

 * @defer_sync: Hook to global list of devices that have deferred sync_state.

 * @defer_hook: Hook to global list of devices that have deferred sync_state or

 *		deferred fw_devlink.

 * @need_for_probe: If needs_suppliers is on a list, this indicates if the

 *		    suppliers are needed for probe or not.

 * @status: Driver status information.
@@ -442,7 +443,7 @@ struct dev_links_info { 
	struct list_head suppliers;

	struct list_head consumers;

	struct list_head needs_suppliers;

	struct list_head defer_sync;

	struct list_head defer_hook;

	bool need_for_probe;

	enum dl_dev_state status;

};

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