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 X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 018A4C4332F for ; Wed, 15 Sep 2021 09:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5C4661244 for ; Wed, 15 Sep 2021 09:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237176AbhIOJZN (ORCPT ); Wed, 15 Sep 2021 05:25:13 -0400 Received: from mail.aperture-lab.de ([116.203.183.178]:57710 "EHLO mail.aperture-lab.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229785AbhIOJZM (ORCPT ); Wed, 15 Sep 2021 05:25:12 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id DA9C93EA68; Wed, 15 Sep 2021 11:23:45 +0200 (CEST) Date: Wed, 15 Sep 2021 11:23:43 +0200 From: Linus =?utf-8?Q?L=C3=BCssing?= To: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= Cc: Kalle Valo , Felix Fietkau , Sujith Manoharan , ath9k-devel@qca.qualcomm.com, linux-wireless@vger.kernel.org, "David S . Miller" , Jakub Kicinski , "John W . Linville" , Felix Fietkau , Simon Wunderlich , Sven Eckelmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] ath9k: interrupt fixes on queue reset Message-ID: References: <20210914192515.9273-1-linus.luessing@c0d3.blue> <87a6kf6iip.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87a6kf6iip.fsf@toke.dk> X-Last-TLS-Session-Version: TLSv1.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Toke, On Tue, Sep 14, 2021 at 09:53:34PM +0200, Toke Høiland-Jørgensen wrote: > Linus Lüssing writes: > > > Hi, > > > > The following are two patches for ath9k to fix a potential interrupt > > storm (PATCH 2/3) and to fix potentially resetting the wifi chip while > > its interrupts were accidentally reenabled (PATCH 3/3). > > Uhh, interesting - nice debugging work! What's the user-level symptom of > this? I.e., when this triggers does the device just appear to hang, or > does it cause reboots, or? > > -Toke > For PATCH 2/3 the user-level symptom was that the system would hang for a few seconds and would then silently reboot without any notice on the serial console. And after disabling CONFIG_ATH79_WDT the system would "hang" indefinitely without any notice on the console without a reboot (while JTAG/gdb showed that it was entering ath_isr() again and again and wasn't doing anything else). For PATCH 3/3 I don't have a specific user-level symptom. But from looking at the git history it seemed to me that the ath9k hw interrupts (AR_IER, AR_INTR_ASYNC_ENABLE and AR_INTR_ASYNC_ENABLE off) should be disabled during a reset: 4668cce527ac ath9k: disable the tasklet before taking the PCU lock eaf04a691566 ath9k: Disable beacon tasklet during reset 872b5d814f99 ath9k: do not access hardware on IRQs during reset e3f31175a3ee ath9k: fix race condition in irq processing during hardware reset Maybe someone else on these lists might know what issues this can cause exactly? Regards, Linus