Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:57414 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729583AbeGQPlI (ORCPT ); Tue, 17 Jul 2018 11:41:08 -0400 Subject: Re: Setting tx retry count in ath10k To: SEDE , Benjamin Beichler , ath10k , "linux-wireless@vger.kernel.org" References: <8b9713fe-7573-f009-d002-13df73315898@televic.com> From: Ben Greear Message-ID: <9dd76e58-b514-26f2-2fe9-0c9a7f798054@candelatech.com> (sfid-20180717_170806_674025_EE344CC6) Date: Tue, 17 Jul 2018 08:07:55 -0700 MIME-Version: 1.0 In-Reply-To: <8b9713fe-7573-f009-d002-13df73315898@televic.com> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 07/17/2018 12:56 AM, SEDE wrote: > Hi, > > In the standard, 7 is the default for the short retry count, 4 is well the default for long retry count. > > In ath10k, there is also non_agg_sw_retry_th to control this, will this still be used? > Or what is the difference with rc_num_retries? > > Kind regards, > Sébastien. The ath10k firmware has no idea of long vs short retries, so I just used the long setting. I will investigate that non_agg_sw_retry_th as well, and I did notice my wave-1 firmware (at least) uses 15 retries for self-generated frames. But, in my case, those self-gen frames are not much used anyway since I disable firmware keep-alive. And, I need to see how the mac80211 stack handles its own retries when working with ath10k. Thanks, Ben > > > On 2018-07-17 09:39, Benjamin Beichler wrote: >> Hi, >> >> Am 17.07.2018 um 02:37 schrieb Ben Greear: >>> I spent a bit of time looking into setting the tx retry count in >>> ath10k (wave-1 firmware). The firmware has support for setting this as >>> a vdev parameter, and it defaults to '2', at least in my wave-1 firmware. >>> >>> I enabled propagating the setting from mac80211, ie: >>> iw phy wiphy0 set retry short 2 long 2 >>> >>> And while debugging this, I noticed that mac80211 has a default of >>> 4, but the ath10k firmware has a default of 2. Now, I am not sure >>> if I should enable setting the retry count since it will change >>> the behaviour even if users don't set anything. >>> >> Maybe I'm wrong, but I have in mind, that 7 retries is the default >> setting of mac80211. Although 2 or even 4 seems to be pretty low for the >> overall retry count, so maybe the values are somehow changed in the >> firmware? From our experiments we know (at least for 802.11n) you need >> for normal operation a retry count of something between 5 - 9, but >> sometimes also 12 or 15 is beneficial. >> >> We use for our experimental setup mainly ath9k cards and rt28xx nics, >> and with them you need definitely more retries. >> >> Nonetheless, I don't think the change from 2 to 4 does really affect the >> behavior in a negative way (if it works as expected). >> >>> Any opinions on this? >>> >>> Thanks, >>> Ben >>> > -- Ben Greear Candela Technologies Inc http://www.candelatech.com