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 1YQjJX-00072z-4J for ath10k@lists.infradead.org; Wed, 25 Feb 2015 21:16:15 +0000 Message-ID: <54EE3B89.6070803@candelatech.com> Date: Wed, 25 Feb 2015 13:15:53 -0800 From: Ben Greear MIME-Version: 1.0 Subject: Re: Question on setting tx-power in ath10k. References: <54EE1355.3010306@candelatech.com> 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: Adrian Chadd Cc: ath10k On 02/25/2015 11:55 AM, Adrian Chadd wrote: > Yeah I remember this stuff. ath9k did the same thing too; it subtracts > TX power based on 2-chain and 3-chain; assuming that the max transmit > power in the EEPROM is actually the 3-chain value so it can get the > per-chain transmit power. > > Thing is, whenever I actually looked at the output on a spectrum > analyser, the target power differed from what the card was rated at by > exactly 3 and 5 dBm respectively. Grr. > > In FreeBSD I look at the number of configured chains for that TX > attempt and set the TX power cap appropriately per-packet. Grr. We have a spectrum analyzer now, but I'm not sure if I can even force the NIC to run at a specific HT or VHT rate, so not so sure how to test the changes properly. Either way, even if I adjust this as I am trying to do now (on a per-rate basis based on number of chains that rate uses) the min/max power restraints stay in place, so it should still be fine as far as regulations are concerned. Thanks for the info. Ben > > > -adrian > > On 25 February 2015 at 10:24, Ben Greear wrote: >> I have added some debugging in my CT firmware based on 10.1.467, and I have noticed >> that anything below 5db is treated as zero by the firmware. This is due primarily to >> subtracting a fixed amount based on the NIC's configured chainmask. >> >> I am guessing this is not entirely correct, since at /b rates, for instance, we >> will be transmitting on only a single chain, so it does not matter how many >> chains the hardware has? >> >> Anyone have any insight on how this stuff is *supposed* to work? >> >> If you have access to firmware source, plz contact me off the mailing list >> and I can provide more details about the code that looks broken. >> >> 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 > -- Ben Greear Candela Technologies Inc http://www.candelatech.com _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k