Git is the recommended way as it makes it quite easy to create and send working patch emails, but you are not required to use it.
b) Can I submit a patch against HEAD on a branch (e.g. 14.07) or only
Patches should be against trunk and will be backported to affected branches if needed. If the issue only affects the branch, then a patch against the branch is fine. This is to ensure that fixes can't get “lost” in a branch.
c) Which commands of the many possible git permutations should I use the
generate the patch ?
git format-patch is what I use.
My workflow is basically (for a single patch)
a) edit stuff b) ensure it compiles c) git add <modified/new files> d) git commit -s e) <add proper subject in first line, empty line, commit message> f) git show -1 (to review the patch) g) git format-patch -1 h) scripts/checkpatch.pl 0001-* i) git send-email --to=... --cc=... 0001-*
for patch series, do a to f accordingly, then git format-patch -<x>, where x = number of patches, or <rev> (maybe also a –cover-letter), then send the patch series.