I discovered that if EMBEDDED=y, one can accidentally build a mac80211 stack w/ no rate control algorithm. When RC_MINISTREL and RC_PID are both disabled, the RC_DEFAULT string (which rate.c uses as the fallback algorithm) will be "". That'll cause the rate_control_alloc to fail, which will in turn cause ieee80211_register_hw to fail. IOW, no driver will load. This will tell kconfig to provide a warning if no rate control algorithms have been selected. That'll at least warn the user that they're about to build a broken wireless stack. Signed-off-by: Andres Salomon <dilinger@xxxxxxxxxxxxxxx> --- net/mac80211/Kconfig | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig index a10d508..1f0ebab 100644 --- a/net/mac80211/Kconfig +++ b/net/mac80211/Kconfig @@ -15,8 +15,12 @@ comment "CFG80211 needs to be enabled for MAC80211" if MAC80211 != n +config MAC80211_HAS_RC + def_bool n + config MAC80211_RC_PID bool "PID controller based rate control algorithm" if EMBEDDED + select MAC80211_HAS_RC ---help--- This option enables a TX rate control algorithm for mac80211 that uses a PID controller to select the TX @@ -24,12 +28,14 @@ config MAC80211_RC_PID config MAC80211_RC_MINSTREL bool "Minstrel" if EMBEDDED + select MAC80211_HAS_RC default y ---help--- This option enables the 'minstrel' TX rate control algorithm choice prompt "Default rate control algorithm" + depends on MAC80211_HAS_RC default MAC80211_RC_DEFAULT_MINSTREL ---help--- This option selects the default rate control algorithm @@ -62,6 +68,9 @@ config MAC80211_RC_DEFAULT endif +comment "mac80211 will not work properly w/out rate control algorithm" + depends on MAC80211_HAS_RC=n + config MAC80211_MESH bool "Enable mac80211 mesh networking (pre-802.11s) support" depends on MAC80211 && EXPERIMENTAL -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html