[PATCH 3/3] docs: sysctl/kernel: document firmware_config

[Stephen Kitt]

Based on the firmware fallback mechanisms documentation and the
implementation in drivers/base/firmware_loader/fallback.c.

Signed-off-by: Stephen Kitt <steve@xxxxxxx>
---
 Documentation/admin-guide/sysctl/kernel.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index d4bbdaf96ebc..cb6d5302b595 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -265,6 +265,19 @@ domain names are in general different. For a detailed discussion
 see the ``hostname(1)`` man page.
 
 
+firmware_config
+===============
+
+See :doc:`/driver-api/firmware/fallback-mechanisms`.
+
+The entries in this directory allow the firmware loader helper
+fallback to be controlled:
+
+* ``force_sysfs_fallback``, when set to 1, forces the use of the
+  fallback;
+* ``ignore_sysfs_fallback``, when set to 1, ignores any fallback.
+
+
 ftrace_dump_on_oops
 ===================
 
-- 
2.20.1