Re: [PATCH 05/15] mac80211: remove HW_KEY_IDX_INVALID

[Larry Finger <larry.finger@lwfinger.net>]

Johannes Berg wrote:

The following hunk in wireless-dev/include/net/mac80211.h

@@ -200,13 +199,13 @@ struct ieee80211_tx_control {
  						  * long retry value */
  	u32 flags;			       /* tx control flags defined
  						* above */
+	u8 key_idx;		/* keyidx from hw->set_key(), undefined if
+				 * IEEE80211_TXCTL_DO_NOT_ENCRYPT is set */
  	u8 retry_limit;		/* 1 = only first attempt, 2 = one retry, ..
  				 * This could be used when set_retry_limit
  				 * is not implemented by the driver */
  	u8 power_level;		/* per-packet transmit power level, in dBm */
  	u8 antenna_sel_tx; 	/* 0 = default/diversity, 1 = Ant0, 2 = Ant1 */
-	s8 key_idx;		/* HW_KEY_IDX_INVALID = do not encrypt,
-				 * other values: keyidx from hw->set_key() */
  	u8 icv_len;		/* length of the ICV/MIC field in octets */
  	u8 iv_len;		/* length of the IV field in octets */
  	u8 tkip_key[16];	/* generated phase2/phase1 key for hw TKIP */

leads to a compiler warning "warning: comparison is always true due to limited range of data type" 
for b43 and b43legacy on the fiollowing statement.

         int use_encryption = ((!(txctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
                               && (txctl->key_idx >= 0));

What did a negative key_idx mean before? How is that condition represented now, or is it safe to 
drop the entire portion following the &&?

Thanks,

Larry