36  * Deferred Probe infrastructure.
38  * Sometimes driver probe order matters, but the kernel doesn't always have
43  * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
45  * Deferred probe maintains two lists of devices, a pending list and an active
47  * pending list.  A successful driver probe will trigger moving all devices
60 /* Save the async probe drivers' name from kernel cmdline */
87 	 * bus_probe_device() to re-attempt the probe.  The loop continues  in deferred_probe_work_func()
108 		 * Drop the mutex while probing each device; the probe path may  in deferred_probe_work_func()
117 		 * probe makes that very unsafe.  in deferred_probe_work_func()
160  * list and schedules the deferred probe workqueue to process them.  It
163  * Note, there is a race condition in multi-threaded probe. In the case where
165  * probe to complete successfully while another is about to defer. If the second
171  * changes in the midst of a probe, then deferred processing should be triggered
180 	 * A successful probe means that all the devices in the pending list  in driver_deferred_probe_trigger()
191 	 * Kick the re-probe thread.  It may already be scheduled, but it is  in driver_deferred_probe_trigger()
222  * device_set_deferred_probe_reason() - Set defer probe reason message for device
240  * deferred_devs_show() - Show the devices in the deferred probe pending list.
273  * driver_deferred_probe_check_state() - Check deferred probe state
278  * -ETIMEDOUT if the deferred probe timeout was set and has expired
293 		dev_warn(dev, "deferred probe timeout, ignoring dependency\n");  in driver_deferred_probe_check_state()
312 		dev_info(p->device, "deferred probe pending\n");  in deferred_probe_timeout_work_func()
340 	 * Trigger deferred probe again, this time we won't defer anything  in deferred_probe_initcall()
471  * (It is ok to call with no other effort from a driver's probe() method.)
514 	if (dev->bus->probe)  in call_driver_probe()
515 		ret = dev->bus->probe(dev);  in call_driver_probe()
516 	else if (drv->probe)  in call_driver_probe()
517 		ret = drv->probe(dev);  in call_driver_probe()
524 		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);  in call_driver_probe()
528 		pr_debug("%s: probe of %s rejects match %d\n",  in call_driver_probe()
532 		/* driver matched but the probe failed */  in call_driver_probe()
533 		pr_warn("%s: probe of %s failed with error %d\n",  in call_driver_probe()
553 		dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);  in really_probe()
599 		 * Return probe errors as positive values so that the callers  in really_probe()
681  * For initcall_debug, show the driver probe time.
691 	pr_debug("probe of %s returned %d after %lld usecs\n",  in really_probe_debug()
698  * Determine if the probe sequence is finished or not.
718 	/* wait for probe timeout */  in wait_for_device_probe()
721 	/* wait for the deferred probe workqueue to finish */  in wait_for_device_probe()
768  * (inverted) error code for failures from the ->probe method.
853 	 * probe for given device and driver from bus_for_each_drv() since
878 		dev_dbg(dev, "Device match requests probe deferral\n");  in __device_attach_driver()
895 	 * Ignore errors returned by ->probe so that the next driver can try  in __device_attach_driver()
918 	 * and deferred probe processing happens all at once with  in __device_attach_async_helper()
928 	dev_dbg(dev, "async probe completed\n");  in __device_attach_async_helper()
976 			 * want to probe asynchronously, we'll  in __device_attach()
979 			dev_dbg(dev, "scheduling asynchronous probe\n");  in __device_attach()
1067 	/* also return probe errors as normal negative errnos */  in device_driver_attach()
1112 		dev_dbg(dev, "Device match requests probe deferral\n");  in __driver_attach()
1123 		 * probe it asynchronously to allow for more parallelism.  in __driver_attach()