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: linux-pm@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/r/20200225050828.56458-6-john.stultz@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/dd.c

@@ -229,17 +229,19 @@ DEFINE_SHOW_ATTRIBUTE(deferred_devs);
  * 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);
@@ -264,7 +266,7 @@ int driver_deferred_probe_check_state(struct device *dev)
 		return -ENODEV;
 	}
 
-	if (!deferred_probe_timeout) {
+	if (!driver_deferred_probe_timeout) {
 		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
 		return -ETIMEDOUT;
 	}
@@ -276,7 +278,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
 	struct device_private *private, *p;
 
-	deferred_probe_timeout = 0;
+	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
@@ -310,9 +312,9 @@ static int deferred_probe_initcall(void)
 	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

@@ -236,6 +236,7 @@ driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
 }
 #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);