35  * Deferred Probe infrastructure.
37  * Sometimes driver probe order matters, but the kernel doesn't always have
42  * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
44  * Deferred probe maintains two lists of devices, a pending list and an active
46  * pending list.  A successful driver probe will trigger moving all devices
77 	 * bus_probe_device() to re-attempt the probe.  The loop continues  in deferred_probe_work_func()
96 		 * Drop the mutex while probing each device; the probe path may  in deferred_probe_work_func()
105 		 * probe makes that very unsafe.  in deferred_probe_work_func()
144  * list and schedules the deferred probe workqueue to process them.  It
147  * Note, there is a race condition in multi-threaded probe. In the case where
149  * probe to complete successfully while another is about to defer. If the second
155  * changes in the midst of a probe, then deferred processing should be triggered
164 	 * A successful probe means that all the devices in the pending list  in driver_deferred_probe_trigger()
175 	 * Kick the re-probe thread.  It may already be scheduled, but it is  in driver_deferred_probe_trigger()
206  * deferred_devs_show() - Show the devices in the deferred probe pending list.
232  * driver_deferred_probe_check_state() - Check deferred probe state
236  * to probe (i.e. initcalls are done), -ETIMEDOUT if deferred probe debug
246 			dev_WARN(dev, "deferred probe timeout, ignoring dependency");  in driver_deferred_probe_check_state()
264 		dev_info(private->device, "deferred probe pending");  in deferred_probe_timeout_work_func()
287 	 * Trigger deferred probe again, this time we won't defer anything  in deferred_probe_initcall()
416  * from a driver's probe() method.)
459 		dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);  in really_probe()
503 	if (dev->bus->probe) {  in really_probe()
504 		ret = dev->bus->probe(dev);  in really_probe()
507 	} else if (drv->probe) {  in really_probe()
508 		ret = drv->probe(dev);  in really_probe()
562 		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);  in really_probe()
567 		pr_debug("%s: probe of %s rejects match %d\n",  in really_probe()
571 		/* driver matched but the probe failed */  in really_probe()
573 		       "%s: probe of %s failed with error %d\n",  in really_probe()
577 	 * Ignore errors returned by ->probe so that the next driver can try  in really_probe()
588  * For initcall_debug, show the driver probe time.
599 	printk(KERN_DEBUG "probe of %s returned %d after %lld usecs\n",  in really_probe_debug()
606  * Determine if the probe sequence is finished or not.
625 	/* wait for the deferred probe workqueue to finish */  in wait_for_device_probe()
712 	 * probe for given device and driver from bus_for_each_drv() since
737 		dev_dbg(dev, "Device match requests probe deferral\n");  in __device_attach_driver()
769 	 * and deferred probe processing happens all at once with  in __device_attach_async_helper()
779 	dev_dbg(dev, "async probe completed\n");  in __device_attach_async_helper()
827 			 * want to probe asynchronously, we'll  in __device_attach()
830 			dev_dbg(dev, "scheduling asynchronous probe\n");  in __device_attach()
890 		dev_dbg(dev, "Device match requests probe deferral\n");  in __driver_attach()