On Sunday 02 December 2012 11:42:38 Dan Carpenter wrote: > The "sta" variable is not checked for NULL consistently and it makes the > static checkers complain. I asked Christian Lamparter about this and > it turns out the check is not needed. "In fact, in order to set up a > ampdu session, the stack would call the driver's op_ampdu_action > callback which always needs a station." that would be from the thread: <http://www.spinics.net/lists/linux-wireless/msg94526.html> > I have removed the check. I think this will bug for multicast and injected frames. It is not possible for the sta(tion) pointer to be NULL if the frame has the IEEE80211_TX_CTL_AMPDU flag set. So the sta == NULL check can be avoided when calling carl9170_tx_ampdu_queue. This is because mac80211 tracks all aggregation sessions within the station struct. Of course, this is something that the checker tool can't possibly deduce, but it has a point and we can add a check like this [see attached draft patch]: What do you think [or more to the point: what does the checker say?] Regards, Chr --- diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c index 84377cf..e09d293 100644 --- a/drivers/net/wireless/ath/carl9170/tx.c +++ b/drivers/net/wireless/ath/carl9170/tx.c @@ -1470,6 +1470,9 @@ void carl9170_op_tx(struct ieee80211_hw *hw, info = IEEE80211_SKB_CB(skb); + if ((info->flags & IEEE80211_TX_CTL_AMPDU) && WARN_ON_ONCE(!sta)) + goto err_free; + if (unlikely(carl9170_tx_prepare(ar, sta, skb))) goto err_free; -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
