[PATCH net] docs: netdev: Document guidance on inline functions

[Simon Horman <horms@kernel.org>]

Document preference for non inline functions in .c files.
This has been the preference for as long as I can recall
and I was recently surprised to discover that it is undocumented.

Reported-by: Alexandre Ferrieux <alexandre.ferrieux@gmail.com>
Closes: https://lore.kernel.org/all/9662e6fe-cc91-4258-aba1-ab5b016a041a@orange.com/
Signed-off-by: Simon Horman <horms@kernel.org>
---
 Documentation/process/maintainer-netdev.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/process/maintainer-netdev.rst b/Documentation/process/maintainer-netdev.rst
index e497729525d5..1fbb8178b8cd 100644
--- a/Documentation/process/maintainer-netdev.rst
+++ b/Documentation/process/maintainer-netdev.rst
@@ -408,6 +408,17 @@ at a greater cost than the value of such clean-ups.
 
 Conversely, spelling and grammar fixes are not discouraged.
 
+Inline functions
+----------------
+
+The use of static inline functions in .c file is strongly discouraged
+unless there is a demonstrable reason for them, usually performance
+related. Rather, it is preferred to omit the inline keyword and allow the
+compiler to inline them as it sees fit.
+
+This is a stricter requirement than that of the general Linux Kernel
+:ref:`Coding Style<codingstyle>`
+
 Resending after review
 ~~~~~~~~~~~~~~~~~~~~~~