[PATCH RFC 1/4] kmod: add a routine to return if usermode is disabled

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Several media devices are only capable of probing the device if
the firmware load is enabled, e. g. when the usermode var is not
disabled.

Add a routine to allow those drivers to test if probe can continue
or need to be deferred.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 include/linux/firmware.h |    6 ++++++
 kernel/kmod.c            |    6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index 1e7c011..cacf27e 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -35,6 +35,12 @@ struct builtin_fw {
 	static const struct builtin_fw __fw_concat(__builtin_fw,__COUNTER__) \
 	__used __section(.builtin_fw) = { name, blob, size }
 
+/**
+ * is_usermodehelp_disabled - returns true if firmware usermode is disabled
+ *			      false otherwise.
+ */
+bool is_usermodehelp_disabled(void);
+
 #if defined(CONFIG_FW_LOADER) || (defined(CONFIG_FW_LOADER_MODULE) && defined(MODULE))
 int request_firmware(const struct firmware **fw, const char *name,
 		     struct device *device);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 05698a7..68901308 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -339,6 +339,12 @@ static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
  */
 static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq);
 
+bool is_usermodehelp_disabled(void)
+{
+	return usermodehelper_disabled ? true : false;
+}
+EXPORT_SYMBOL_GPL(is_usermodehelp_disabled);
+
 /*
  * Time to wait for running_helpers to become zero before the setting of
  * usermodehelper_disabled in usermodehelper_disable() fails
-- 
1.7.10.2