Documentation: update stable review cycle documentation

In recent times, the review cycle for stable releases have been changed.
In particular, there is release candidate phase between ACKing patches
and new stable release. Also, in case of failed submissions (fail to
apply to stable tree), manual backport (Option 3) have to be submitted
instead.

Update the release cycle documentation on stable-kernel-rules.rst to
reflect the above.

Cc: Sasha Levin <sashal@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20220314113329.485372-4-bagasdotme@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/process/stable-kernel-rules.rst

@@ -83,8 +83,8 @@ it to be applied to.
 :ref:`option_2` and :ref:`option_3` are more useful if the patch isn't deemed
 worthy at the time it is applied to a public git tree (for instance, because
 it deserves more regression testing first).  :ref:`option_3` is especially
-useful if the patch needs some special handling to apply to an older kernel
-(e.g., if API's have changed in the meantime).
+useful if the original upstream patch needs to be backported (for example
+the backport needs some special handling due to e.g. API changes).
 
 Note that for :ref:`option_3`, if the patch deviates from the original
 upstream patch (for example because it had to be backported) this must be very
@@ -153,8 +153,17 @@ Review cycle
  - If the patch is rejected by a member of the committee, or linux-kernel
    members object to the patch, bringing up issues that the maintainers and
    members did not realize, the patch will be dropped from the queue.
- - At the end of the review cycle, the ACKed patches will be added to the
-   latest -stable release, and a new -stable release will happen.
+ - The ACKed patches will be posted again as part of release candidate (-rc)
+   to be tested by developers and testers.
+ - Usually only one -rc release is made, however if there are any outstanding
+   issues, some patches may be modified or dropped or additional patches may
+   be queued. Additional -rc releases are then released and tested until no
+   issues are found.
+ - Responding to the -rc releases can be done on the mailing list by sending
+   a "Tested-by:" email with any testing information desired. The "Tested-by:"
+   tags will be collected and added to the release commit.
+ - At the end of the review cycle, the new -stable release will be released
+   containing all the queued and tested patches.
  - Security patches will be accepted into the -stable tree directly from the
    security kernel team, and not go through the normal review cycle.
    Contact the kernel security team for more details on this procedure.