Merge branch 'netdev-docs'

Jakub Kicinski says:

====================
docs: netdev: document more of our rules

The patch series length limit and reverse xmas tree are not documented.
Add those, and a tl;dr section summarizing how we differ.

v2: improve the series length blurb (Andrew)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/process/maintainer-netdev.rst

@@ -6,6 +6,15 @@
 netdev FAQ
 ==========
 
+tl;dr
+-----
+
+ - designate your patch to a tree - ``[PATCH net]`` or ``[PATCH net-next]``
+ - for fixes the ``Fixes:`` tag is required, regardless of the tree
+ - don't post large series (> 15 patches), break them up
+ - don't repost your patches within one 24h period
+ - reverse xmas tree
+
 What is netdev?
 ---------------
 It is a mailing list for all network-related Linux stuff.  This
@@ -136,6 +145,20 @@ it to the maintainer to figure out what is the most recent and current
 version that should be applied. If there is any doubt, the maintainer
 will reply and ask what should be done.
 
+How do I divide my work into patches?
+-------------------------------------
+
+Put yourself in the shoes of the reviewer. Each patch is read separately
+and therefore should constitute a comprehensible step towards your stated
+goal.
+
+Avoid sending series longer than 15 patches. Larger series takes longer
+to review as reviewers will defer looking at it until they find a large
+chunk of time. A small series can be reviewed in a short time, so Maintainers
+just do it. As a result, a sequence of smaller series gets merged quicker and
+with better review coverage. Re-posting large series also increases the mailing
+list traffic.
+
 I made changes to only a few patches in a patch series should I resend only those changed?
 ------------------------------------------------------------------------------------------
 No, please resend the entire patch series and make sure you do number your
@@ -183,6 +206,19 @@ it is requested that you make it look like this::
    * another line of text
    */
 
+What is "reverse xmas tree"?
+----------------------------
+
+Netdev has a convention for ordering local variables in functions.
+Order the variable declaration lines longest to shortest, e.g.::
+
+  struct scatterlist *sg;
+  struct sk_buff *skb;
+  int err, i;
+
+If there are dependencies between the variables preventing the ordering
+move the initialization out of line.
+
 I am working in existing code which uses non-standard formatting. Which formatting should I use?
 ------------------------------------------------------------------------------------------------
 Make your code follow the most recent guidelines, so that eventually all code