Re: [PATCH] wifi: mac80211: convert PS buffering into iTXQ

From: Dan Carpenter <error27@gmail.com>
To: Alexander Wetzel <alexander@wetzel-home.de>
Cc: oe-kbuild@lists.linux.dev, linux-wireless@vger.kernel.org,
	lkp@intel.com, oe-kbuild-all@lists.linux.dev,
	Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [PATCH] wifi: mac80211: convert PS buffering into iTXQ
Date: Mon, 7 Nov 2022 16:59:26 +0300	[thread overview]
Message-ID: <Y2kPPn7qmao4VL5y@kadam> (raw)
In-Reply-To: <08af0517-fb5f-cfd1-e92b-18306603144f@wetzel-home.de>

On Mon, Nov 07, 2022 at 02:52:55PM +0100, Alexander Wetzel wrote:
> Hi,
> 
> On 07.11.22 09:00, Dan Carpenter wrote:
> > Hi Alexander,
> > 
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > 
> > url:    https://github.com/intel-lab-lkp/linux/commits/Alexander-Wetzel/wifi-mac80211-convert-PS-buffering-into-iTXQ/20221101-100832
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git main
> > patch link:    https://lore.kernel.org/r/20221031211815.6666-1-alexander%40wetzel-home.de
> > patch subject: [PATCH] wifi: mac80211: convert PS buffering into iTXQ
> > config: openrisc-randconfig-m041-20221106
> > compiler: or1k-linux-gcc (GCC) 12.1.0
> > 
> > If you fix the issue, kindly add following tag where applicable
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Reported-by: Dan Carpenter <error27@gmail.com>
> > 
> > New smatch warnings:
> > net/mac80211/tx.c:1145 ieee80211_get_txq() warn: variable dereferenced before check 'vif' (see line 1112)
> 
> vif can't be null here, the existing null check is not needed.
> 
> ieee80211_get_txq() is only used in ieee80211_queue_skb(). Which already
> access sdata->vif.type and sets vif to &sdata->vif prior of calling
> ieee80211_get_txq();
> 
> Would dropping the null check in line 1145 be an acceptable solution to get
> rid of this warning?
> 
> I'll then would do that in the next revision (v3) of the patch and send that
> out after either Johannes has reviewed v2 or serious issues are discovered
> by anyone.
> 

You should probably delete the NULL check in a separate patch (I say
without looking at any of your patches).

This is a Smatch warning and not a GCC warning so it's not like the NULL
check hurts anything besides readability.

regards,
dan carpenter