mac80211: better rate control algorithm selection

This patch changes mac80211's Kconfig/Makefile to:
 * select between the PID and the SIMPLE rate control
   algorithm as default
 * always allow tri-state for the rate control algorithms,
   building those that are selected 'y' into the mac80211
   module (if that is a module, otherwise all into the kernel)
 * force the default rate control algorithm to be built into
   mac80211

It also makes both rate control algorithms proper modules again
with MODULE_LICENSE etc.

Only if EMBEDDED is the user allowed to select "NONE" as default
which will cause no algorithm to be selected, this will work
only when the driver brings one itself (e.g. iwlwifi drivers).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 19 deletions

diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index cac6cf2e9ac8..09c255002e56 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -13,25 +13,17 @@ config MAC80211
           This option enables the hardware independent IEEE 802.11
           networking stack.
 
-config MAC80211_RC_DEFAULT_CHOICE
-        bool "Choose default rate control algorithm" if EMBEDDED
-        default y
-        depends on MAC80211
-        ---help---
-          This options enables selection of a default rate control
-          algorithm to be built into the mac80211 module.  Alternate
-          rate control algorithms might be built into the mac80211
-          module as well.
+menu "Rate control algorithm selection"
+        depends on MAC80211 != n
 
 choice
         prompt "Default rate control algorithm"
         default MAC80211_RC_DEFAULT_PID
-        depends on MAC80211 && MAC80211_RC_DEFAULT_CHOICE
         ---help---
           This option selects the default rate control algorithm
           mac80211 will use. Note that this default can still be
           overriden through the ieee80211_default_rc_algo module
-          parameter.
+          parameter if different algorithms are available.
 
 config MAC80211_RC_DEFAULT_PID
         bool "PID controller based rate control algorithm"
@@ -50,19 +42,27 @@ config MAC80211_RC_DEFAULT_SIMPLE
           dumb algorithm. You should choose the PID rate control
           instead.
 
+config MAC80211_RC_DEFAULT_NONE
+        bool "No default algorithm"
+        depends on EMBEDDED
+        help
+          Selecting this option will select no default algorithm
+          and allow you to not build any. Do not choose this
+          option unless you know your driver comes with another
+          suitable algorithm.
 endchoice
 
+comment "Selecting 'y' for an algorithm will"
+comment "build the algorithm into mac80211."
+
 config MAC80211_RC_DEFAULT
         string
-        depends on MAC80211
         default "pid" if MAC80211_RC_DEFAULT_PID
         default "simple" if MAC80211_RC_DEFAULT_SIMPLE
         default ""
 
 config MAC80211_RC_PID
-        bool "PID controller based rate control algorithm"
-        default y
-        depends on MAC80211
+        tristate "PID controller based rate control algorithm"
         ---help---
           This option enables a TX rate control algorithm for
           mac80211 that uses a PID controller to select the TX
@@ -72,16 +72,15 @@ config MAC80211_RC_PID
           different rate control algorithm.
 
 config MAC80211_RC_SIMPLE
-        bool "Simple rate control algorithm (DEPRECATED)"
-        default n
-        depends on MAC80211
+        tristate "Simple rate control algorithm (DEPRECATED)"
         ---help---
           This option enables a very simple, non-responsive TX
           rate control algorithm. This algorithm is deprecated
-          and will be removed from the kernel in near future.
+          and will be removed from the kernel in the near future.
           It has been replaced by the PID algorithm.
 
           Say N unless you know what you are doing.
+endmenu
 
 config MAC80211_LEDS
         bool "Enable LED triggers"