madwifi: if a txpower value below the poweroffset is requested, set the internal txpower to 0db

SVN-Revision: 16234

package/madwifi/patches/438-poweroffset_sysctl.patch

@@ -1,5 +1,21 @@
 --- a/ath/if_ath.c
 +++ b/ath/if_ath.c
+@@ -10474,11 +10474,11 @@ set_node_txpower(void *arg, struct ieee8
+  * XXX: this function needs some locking to avoid being called 
+  * twice/interrupted. Returns the value actually stored. */
+ static u_int32_t
+-ath_set_clamped_maxtxpower(struct ath_softc *sc, 
+-		u_int32_t new_clamped_maxtxpower)
++ath_set_clamped_maxtxpower(struct ath_softc *sc, u_int32_t new_txpwr)
+ {
+-	new_clamped_maxtxpower -= sc->sc_poweroffset;
+-	(void)ath_hal_settxpowlimit(sc->sc_ah, new_clamped_maxtxpower);
++	new_txpwr = ((new_txpwr < sc->sc_poweroffset) ? 0 :
++		new_txpwr - sc->sc_poweroffset);
++	(void)ath_hal_settxpowlimit(sc->sc_ah, new_txpwr);
+ 	return ath_get_clamped_maxtxpower(sc);
+ }
+ 
 @@ -11029,6 +11029,7 @@ enum {
  	ATH_DEBUG,
  	ATH_TXANTENNA,