From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94728C63797 for ; Tue, 10 Jan 2023 15:24:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238540AbjAJPYQ (ORCPT ); Tue, 10 Jan 2023 10:24:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239037AbjAJPXg (ORCPT ); Tue, 10 Jan 2023 10:23:36 -0500 Received: from ns2.wdyn.eu (ns2.wdyn.eu [5.252.227.236]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4648719C21 for ; Tue, 10 Jan 2023 07:23:33 -0800 (PST) Message-ID: <205fb221-f7ad-8f03-2c16-54dcbf5ecaf9@wetzel-home.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wetzel-home.de; s=wetzel-home; t=1673364209; bh=ItZbaDDVl/qbRkDKKGQ9mk0zI8jEClJ48WsBVgPasWg=; h=Date:Subject:To:References:From:In-Reply-To; b=QM2CqeRQkbcwBVz8TtzFHiEdCVZcyI8gse4ibuEH8WQyQ81DNNWDlFt3WSrC311Tw uvOrOd7BgOP13U5wI3/4MUn7mdLdKjF1vhA2j4zYbuWmMl0g8N86KzTd86NzeomO8W ATgNS48FnYpkyM3phWfHhvgn3BdhJqtVVTz0VvyE= Date: Tue, 10 Jan 2023 16:23:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: ieee80211_handle_wake_tx_queue and dynamic ps regression Content-Language: en-US To: Bryan O'Donoghue , linux-kernel@vger.kernel.org, johannes.berg@intel.com, Kalle Valo , linux-wireless@vger.kernel.org References: <19015168-c747-17b7-f0ae-9d2ee27d221c@linaro.org> <06f76774-1b2e-f563-7128-7d5b9547dfe9@linaro.org> From: Alexander Wetzel In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 10.01.23 15:47, Bryan O'Donoghue wrote: > On 10/01/2023 12:44, Bryan O'Donoghue wrote: >> + linux-wireless >> On 10/01/2023 12:35, Bryan O'Donoghue wrote: >>> commit a790cc3a4fad75048295571a350b95b87e022a5a >>> (wake_tx_queue-broken-23-08-01) >>> Author: Alexander Wetzel >>> Date:   Sun Oct 9 18:30:39 2022 +0200 >>> >>>      wifi: mac80211: add wake_tx_queue callback to drivers >>> >>> is causing a regression with >>> >>> - CONF_PS = 1 >>> - CONF_DYNAMIC_PS = 0 >>> - ieee80211_handle_wake_tx_queue >>> >>> In this case we get stuck in a loop similar to this >>> >>> // IEEE80211_CONF_CHANGE_PS >>> [   17.255480] wcn36xx: wcn36xx_change_ps/312 enable >>> [   18.088835] ieee80211_tx_h_dynamic_ps/263 setting >>> IEEE80211_QUEUE_STOP_REASON_PS >>> [   18.088906] ieee80211_handle_wake_tx_queue/334 entry >>> [   18.091505] ieee80211_dynamic_ps_disable_work/2250 calling >>> ieee80211_hw_config() >>> [   18.095370] ieee80211_handle_wake_tx_queue/338 wake_tx_push_queue >>> >>> // IEEE80211_CONF_CHANGE_PS >>> [   18.102625] wcn36xx: wcn36xx_change_ps/312 disable >>> [   18.107643] wake_tx_push_queue/303 entry >>> >>> // txq is stopped here reason == IEEE80211_QUEUE_STOP_REASON_PS >>> [   18.107654] wake_tx_push_queue/311 q_stopped bitmask 0x00000002 >>> IEEE80211_QUEUE_STOP_REASON_PS true >>> [   18.107661] wake_tx_push_queue/324 exit >>> [   18.107667] ieee80211_handle_wake_tx_queue/342 exit >>> [   18.115560] ieee80211_handle_wake_tx_queue/334 entry >>> [   18.139937] ieee80211_handle_wake_tx_queue/338 wake_tx_push_queue >>> [   18.145163] wake_tx_push_queue/303 entry >>> [   18.150016] ieee80211_dynamic_ps_disable_work/2252 completed >>> ieee80211_hw_config() >>> >>> // now we unset IEEE80211_QUEUE_STOP_REASON_PS but too late >>> [   18.151145] wake_tx_push_queue/311 q_stopped bitmask 0x00000002 >>> IEEE80211_QUEUE_STOP_REASON_PS true >>> [   18.155263] ieee80211_dynamic_ps_disable_work/2254 clearing >>> IEEE80211_QUEUE_STOP_REASON_PS >>> [   18.162531] wake_tx_push_queue/324 exit >>> [   18.162548] ieee80211_handle_wake_tx_queue/342 exit >>> [   18.183639] ieee80211_dynamic_ps_disable_work/2259 cleared >>> IEEE80211_QUEUE_STOP_REASON_PS >>> >>> // IEEE80211_CONF_CHANGE_PS runs again >>> [   18.215487] wcn36xx: wcn36xx_change_ps/312 enable >>> >>> We get stuck in that loop. Packets getting transmitted is a rare >>> event, most are dropped. > I'll need some time digest that... I report back once I get it. > BTW I considered implementing a wcn36xx specific wake_tx callback - > which maybe should be done anyway. > > I _don't_ see other drivers checking for q_stopped & > IEEE80211_QUEUE_STOP_REASON_PS > > Should they be ? > No, they should not. My take is, that this is a bug in mac80211. I submitted patches to fixing that, they have just been accepted: https://patchwork.kernel.org/project/linux-wireless/patch/20221230121850.218810-1-alexander@wetzel-home.de/ and https://patchwork.kernel.org/project/linux-wireless/patch/20230106223141.98696-1-alexander@wetzel-home.de/ Can you test if these also help here? > If they should check IEEE80211_QUEUE_STOP_REASON_PS, then right now, > they don't. If they shouldn't check IEEE80211_QUEUE_STOP_REASON_PS then > neither should the generic replacement ieee80211_handle_wake_tx_queue() > > --- > bod