From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:22619 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673Ab2LBQwS (ORCPT ); Sun, 2 Dec 2012 11:52:18 -0500 Date: Sun, 2 Dec 2012 19:51:53 +0300 From: Dan Carpenter To: Christian Lamparter Cc: "John W. Linville" , linux-wireless@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch] carl9170: remove unneeded NULL check Message-ID: <20121202165153.GC6517@mwanda> (sfid-20121202_175223_987725_A82E0FAA) References: <20121202104238.GB16078@elgon.mountain> <201212021449.21267.chunkeey@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <201212021449.21267.chunkeey@googlemail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sun, Dec 02, 2012 at 02:49:20PM +0100, Christian Lamparter wrote: > 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: > > > > 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?] > So we wouldn't apply my patch, we would apply that one instead? I think that's great. My static checker doesn't understand bit flags yet so it would complain but it would be obvious to a human reader. Could you just resend that patch with a signed-off-by? regards, dan carpenter