driver core: add test of driver remove calls during probe

In recent discussions on ksummit-discuss[1], it was suggested to do a
sequence of probe, remove, probe for testing driver remove paths. This
adds a kconfig option for said test.

[1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003459.html

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 98504ec..fdf44ca 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -212,6 +212,16 @@
 
 	  If you are unsure about this, Say N here.
 
+config DEBUG_TEST_DRIVER_REMOVE
+	bool "Test driver remove calls during probe"
+	depends on DEBUG_KERNEL
+	help
+	  Say Y here if you want the Driver core to test driver remove functions
+	  by calling probe, remove, probe. This tests the remove path without
+	  having to unbind the driver or unload the driver module.
+
+	  If you are unsure about this, say N here.
+
 config SYS_HYPERVISOR
 	bool
 	default n