driver core: Rename deferred_probe_timeout and make it global

Since other subsystems (like regulator) have similar arbitrary
timeouts for how long they try to resolve driver dependencies,
rename deferred_probe_timeout to driver_deferred_probe_timeout
and set it as global, so it can be shared.

Cc: [e-mail]
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Linus Walleij <[e-mail]>
Cc: Thierry Reding <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Liam Girdwood <[e-mail]>
Cc: Bjorn Andersson <[e-mail]>
Cc: Saravana Kannan <[e-mail]>
Cc: Todd Kjos <[e-mail]>
Cc: Len Brown <[e-mail]>
Cc: Pavel Machek <[e-mail]>
Cc: Ulf Hansson <[e-mail]>
Cc: Kevin Hilman <[e-mail]>
Cc: "Rafael J. Wysocki" <[e-mail]>
Cc: Rob Herring <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Reviewed-by: Rafael J. Wysocki <[e-mail]>
Signed-off-by: John Stultz <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/base/dd.c

···
  * In the case of modules, set the default probe timeout to
  * 30 seconds to give userland some time to load needed modules
  */
-static int deferred_probe_timeout = 30;
+int driver_deferred_probe_timeout = 30;
 #else
 /* In the case of !modules, no probe timeout needed */
-static int deferred_probe_timeout = -1;
+int driver_deferred_probe_timeout = -1;
 #endif
+EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout);
+
 static int __init deferred_probe_timeout_setup(char *str)
 {
 	int timeout;
 
 	if (!kstrtoint(str, 10, &timeout))
-		deferred_probe_timeout = timeout;
+		driver_deferred_probe_timeout = timeout;
 	return 1;
 }
 __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
···
 		return -ENODEV;
 	}
 
-	if (!deferred_probe_timeout) {
+	if (!driver_deferred_probe_timeout) {
 		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
 		return -ETIMEDOUT;
 	}
···
 {
 	struct device_private *private, *p;
 
-	deferred_probe_timeout = 0;
+	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
···
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
-	if (deferred_probe_timeout > 0) {
+	if (driver_deferred_probe_timeout > 0) {
 		schedule_delayed_work(&deferred_probe_timeout_work,
-			deferred_probe_timeout * HZ);
+			driver_deferred_probe_timeout * HZ);
 	}
 	return 0;
 }

include/linux/device/driver.h

···
 }
 #endif
 
+extern int driver_deferred_probe_timeout;
 void driver_deferred_probe_add(struct device *dev);
 int driver_deferred_probe_check_state(struct device *dev);
 void driver_init(void);