Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:56405 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751479AbaLFISq (ORCPT ); Sat, 6 Dec 2014 03:18:46 -0500 Message-ID: <1417853921.2046.1.camel@sipsolutions.net> (sfid-20141206_091849_745959_F91EF094) Subject: Re: iwlwifi 6235 AGN: hardware limitation on number of stations that can connect in ap mode ? From: Johannes Berg To: Sander Eikelenboom Cc: Intel Linux Wireless , linux-wireless@vger.kernel.org Date: Sat, 06 Dec 2014 09:18:41 +0100 In-Reply-To: <955277702.20141205105522@eikelenboom.it> (sfid-20141205_110059_932860_1A930067) References: <955277702.20141205105522@eikelenboom.it> (sfid-20141205_110059_932860_1A930067) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Sander, > So i'm wondering is there a hardware limitation of stations that can connect to > this mini-pci card in ap-mode ? Yes, there's a hardware/firmware limitation of 16 "station entries". > the first clients connect perfectly well but after 12 client have connected, for > the 13th i get: > > [ 784.301106] wlan0: Allocated STA 00:0d:f0:2e:ee:02 > [ 784.301117] wlan0: moving STA 00:0d:f0:2e:ee:02 to state 2 > [ 784.301122] wlan0: moving STA 00:0d:f0:2e:ee:02 to state 3 > [ 784.301141] iwlwifi 0000:00:05.0: Unable to prepare station 00:0d:f0:2e:ee:02 for addition > [ 784.481399] iwlwifi 0000:00:05.0: Unable to add station 00:0d:f0:2e:ee:02 (-22) > [ 784.647835] wlan0: Destroyed STA 00:0d:f0:2e:ee:02 > [ 785.828588] wlan0: Allocated STA 00:0d:f0:2e:ee:02 > [ 785.828600] wlan0: moving STA 00:0d:f0:2e:ee:02 to state 2 > [ 785.828605] wlan0: moving STA 00:0d:f0:2e:ee:02 to state 3 > [ 785.828624] iwlwifi 0000:00:05.0: Unable to prepare station 00:0d:f0:2e:ee:02 for addition > [ 786.044379] iwlwifi 0000:00:05.0: Unable to add station 00:0d:f0:2e:ee:02 (-22) > [ 786.219632] wlan0: Destroyed STA 00:0d:f0:2e:ee:02 Right. I'm not exactly sure why we put -EINVAL rather than -ENOSPC or something like that, but this is a limitation. > If it is a hardware limitation, are there any other intel mini-pci adapters that > don't have this hardware limitation (or at least a highter one). With the newer 7260/7265 adapters you might be able to go up to 14 or 15 stations (I haven't checked exactly), but that's not a significant increase - the fundamental limit of 16 station entries is still there and at least one is needed for internal tracking for multi-/broadcast transmit transmit (and another one might be reserved for P2P on those devices, and I might be forgetting another one perhaps which would mean 13 is the max) I don't believe that the driver (or even firmware) would be able to work around this. johannes