[PATCH v1 1/3] Revert "driver core: Delete driver_deferred_probe_check_state()"

[Saravana Kannan <saravanak@google.com>]

This reverts commit 9cbffc7a59561be950ecc675d19a3d2b45202b2b.

There are a few more issues to fix that have been reported in the thread
for the original series [1]. We'll need to fix those before this will
work. So, revert it for now.

[1] - https://lore.kernel.org/lkml/20220601070707.3946847-1-saravanak@google.com/

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/dd.c             | 30 ++++++++++++++++++++++++++++++
 include/linux/device/driver.h |  1 +
 2 files changed, 31 insertions(+)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 70f79fc71539..a8916d1bfdcb 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -274,12 +274,42 @@ static int __init deferred_probe_timeout_setup(char *str)
 }
 __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
 
+/**
+ * driver_deferred_probe_check_state() - Check deferred probe state
+ * @dev: device to check
+ *
+ * Return:
+ * * -ENODEV if initcalls have completed and modules are disabled.
+ * * -ETIMEDOUT if the deferred probe timeout was set and has expired
+ *   and modules are enabled.
+ * * -EPROBE_DEFER in other cases.
+ *
+ * Drivers or subsystems can opt-in to calling this function instead of directly
+ * returning -EPROBE_DEFER.
+ */
+int driver_deferred_probe_check_state(struct device *dev)
+{
+	if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
+		dev_warn(dev, "ignoring dependency for device, assuming no driver\n");
+		return -ENODEV;
+	}
+
+	if (!driver_deferred_probe_timeout && initcalls_done) {
+		dev_warn(dev, "deferred probe timeout, ignoring dependency\n");
+		return -ETIMEDOUT;
+	}
+
+	return -EPROBE_DEFER;
+}
+EXPORT_SYMBOL_GPL(driver_deferred_probe_check_state);
+
 static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
 	struct device_private *p;
 
 	fw_devlink_drivers_done();
 
+	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index 7acaabde5396..2114d65b862f 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -242,6 +242,7 @@ driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
 
 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);
 
 /**
-- 
2.37.1.359.gd136c6c3e2-goog