From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail2.candelatech.com ([208.74.158.173]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YkEoI-00009B-G4 for ath10k@lists.infradead.org; Mon, 20 Apr 2015 16:44:39 +0000 Message-ID: <55352CDF.6090901@candelatech.com> Date: Mon, 20 Apr 2015 09:44:15 -0700 From: Ben Greear MIME-Version: 1.0 Subject: Re: Set vht transmission parameters using radiotap header References: <20150418125132.Horde.n2KkWFDIVCdVMjc0WZqgldA@webmail.ugent.be> In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Michal Kazior Cc: Louis Desfossez , "ath10k@lists.infradead.org" On 04/19/2015 10:43 PM, Michal Kazior wrote: > On 18 April 2015 at 12:51, Louis Desfossez wrote: >> Using the click modular router project we are trying to inject packets on an >> Atheros QCA988x in monitor mode. Wireless parameters (nss, mcs, channel, >> guard interval, channel width and tx power) are set in the radiotap header. >> Which parameters can currently be read by the ath10k/mac80211 driver and be >> set for transmission (ie. IEEE_RADIOTAP_DBM_TX_POWER, >> IEEE_RADIOTAP_CHANNEL)? >> Is there a possibility to handle the vht information (ie. >> IEEE80211_RADIOTAP_VHT_MCS, IEEE80211_RADIOTAP_VHT_NSS)? > > By the looks of ieee80211_parse_tx_radiotap() it seems that most > radiotap is ignored on Tx path. > > Anyway I hope you're aware upstream ath10k doesn't support packet injection. > > Also due to firmware design there's no way to specify Tx rate for each > frame. Using per-vdev fixed rate param would require really nasty > hacks in driver. I'm not even sure if it's possible with official > firmware to change mgmt and multicast tx rate (I think CT firmware > from Ben has that). I guess using `iw wlanX set bitrates` explicitly > would be better and cleaner - but first you need to get injection to > work at all. My CT firmware does allow hard-coding the unicast, broadcast, and control-packet rates..but it is not a per-pkt or even per-peer setting. I could probably make it per-peer easily enough if someone cared. I think it would take a good deal of firmware changes to allow per-pkt rate-control from the host, but it seems the firmware was at least originally designed to support this option. I personally would love to move all rate-ctrl out of firmware and onto the host, but it is probably not something I would try myself, and currently there is no good way to share firmware development effort. An interim solution might be to hack my CT firmware to return more tx-status info so that a host based rate-ctrl could do frequent updates to the firmware's rate-ctrl settings to sort of fake host-based rate-ctrl. I might attempt those firmware changes if someone else wanted to handle the bulk of the driver work. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k