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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 CB74BC433DF for ; Fri, 12 Jun 2020 08:23:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A99D4207D8 for ; Fri, 12 Jun 2020 08:23:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591950215; bh=/5txmzz7eCW6JtHsVo5HmBpwrOCoMUZ2cg34Poptxg0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=f6GiwnATH/J/KehrAD6OwZs0O59PA3iPKD6qr74Olx0J3hN2AN+djNY5Gkj9zk0XE qjqBNtHgawh5MHv99bAjgvV4oaC1RV0RQ+G2k35gWX0y8wWYfxNJy2+RdFLETP6uc7 sKz4EsGaARUmbyuCzzJHx9w5pzue5nexjrretqNU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726353AbgFLIXd (ORCPT ); Fri, 12 Jun 2020 04:23:33 -0400 Received: from mail-ed1-f67.google.com ([209.85.208.67]:39807 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726264AbgFLIXd (ORCPT ); Fri, 12 Jun 2020 04:23:33 -0400 Received: by mail-ed1-f67.google.com with SMTP id g1so5812887edv.6; Fri, 12 Jun 2020 01:23:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=W7kjCf2/NPWzaAeHmAsGNvR+U/IDoRneEJh+pNJVKTI=; b=rRwlEsGEidwnhVrlJr8ciBVdEz7z7zNlRfks+dZPjljVIj6O+5mwG4HGk6HuFuvOqx EZtiPFi3tEGm3372WvMTYupVxFk5mY49qzSlM1Oc9HRwvmJfjBHlksK0ahP3diQqql+v 3BKxwhCkW1M9ZDR/F3zMiGHLk0Z19gwafaB5JwttznLTLc2zdEexuLsajTGgw/kvqIHX 57MUJQ0Mu8t48E7zxv74uIjyFGcaU0WGqNjRnM+sAFOZUzg5h+9aBWqc73y/gmHKh2ar A1lRn49p5ysqqwmVPtaGksPjMuPyzmdBl6asnDfeC6duCYuMqFynUcouFeyRbdifaEPy wgGQ== X-Gm-Message-State: AOAM5305kgABOa7HxU36CLhnCyCoSNgvRpFGr4hkSygp0t72xV/Z1I+j OXt5P0DwpYGU25ZKtE6LzJM= X-Google-Smtp-Source: ABdhPJxxAoLFRIexOIimzunGIXKEGJy9vuUQgzNABANWPlkiFc4Cg/PTfeBSdakQzbTCe25y53Zq9g== X-Received: by 2002:a50:f1d9:: with SMTP id y25mr10284528edl.292.1591950211017; Fri, 12 Jun 2020 01:23:31 -0700 (PDT) Received: from pi3 ([194.230.155.184]) by smtp.googlemail.com with ESMTPSA id g22sm2797843edj.63.2020.06.12.01.23.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Jun 2020 01:23:29 -0700 (PDT) Date: Fri, 12 Jun 2020 10:23:27 +0200 From: Krzysztof Kozlowski To: Oleksij Rempel Cc: Fugang Duan , Shawn Guo , Sascha Hauer , linux-kernel@vger.kernel.org, Gao Pan , Oleksij Rempel , Wolfram Sang , NXP Linux Team , Pengutronix Kernel Team , stable@vger.kernel.org, Fabio Estevam , linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org Subject: Re: [PATCH] i2c: imx: Fix external abort on early interrupt Message-ID: <20200612082327.GA25893@pi3> References: <1591796802-23504-1-git-send-email-krzk@kernel.org> <20200612055114.alhm2uakoze6epvf@pengutronix.de> <20200612073815.GA25803@pi3> <20200612080240.73xkiu2esgg6nbp3@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200612080240.73xkiu2esgg6nbp3@pengutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 12, 2020 at 10:02:40AM +0200, Oleksij Rempel wrote: > On Fri, Jun 12, 2020 at 09:38:15AM +0200, Krzysztof Kozlowski wrote: > > On Fri, Jun 12, 2020 at 07:51:14AM +0200, Oleksij Rempel wrote: > > > Hi Krzysztof, > > > > > > thank you for your patch. > > > > > > On Wed, Jun 10, 2020 at 03:46:42PM +0200, Krzysztof Kozlowski wrote: > > > > If interrupt comes early (could be triggered with CONFIG_DEBUG_SHIRQ), > > > > the i2c_imx_isr() will access registers before the I2C hardware is > > > > initialized. This leads to external abort on non-linefetch on Toradex > > > > Colibri VF50 module (with Vybrid VF5xx): > > > > > > > > Unhandled fault: external abort on non-linefetch (0x1008) at 0x8882d003 > > > > Internal error: : 1008 [#1] ARM > > > > Modules linked in: > > > > CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0 #607 > > > > Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree) > > > > (i2c_imx_isr) from [<8017009c>] (free_irq+0x25c/0x3b0) > > > > (free_irq) from [<805844ec>] (release_nodes+0x178/0x284) > > > > (release_nodes) from [<80580030>] (really_probe+0x10c/0x348) > > > > (really_probe) from [<80580380>] (driver_probe_device+0x60/0x170) > > > > (driver_probe_device) from [<80580630>] (device_driver_attach+0x58/0x60) > > > > (device_driver_attach) from [<805806bc>] (__driver_attach+0x84/0xc0) > > > > (__driver_attach) from [<8057e228>] (bus_for_each_dev+0x68/0xb4) > > > > (bus_for_each_dev) from [<8057f3ec>] (bus_add_driver+0x144/0x1ec) > > > > (bus_add_driver) from [<80581320>] (driver_register+0x78/0x110) > > > > (driver_register) from [<8010213c>] (do_one_initcall+0xa8/0x2f4) > > > > (do_one_initcall) from [<80c0100c>] (kernel_init_freeable+0x178/0x1dc) > > > > (kernel_init_freeable) from [<80807048>] (kernel_init+0x8/0x110) > > > > (kernel_init) from [<80100114>] (ret_from_fork+0x14/0x20) > > > > > > > > Additionally, the i2c_imx_isr() could wake up the wait queue > > > > (imx_i2c_struct->queue) before its initialization happens. > > > > > > > > Fixes: 1c4b6c3bcf30 ("i2c: imx: implement bus recovery") > > > > Cc: > > > > Signed-off-by: Krzysztof Kozlowski > > > > > > > > > I assume register access is aborted, because the IP core clock is not > > > enabled. In this case we have bigger problem then just probe. > > > > If by IP core clock you mean the clock which driver is getting, then > > answer is no. This clock is enabled. > > > > > Since this driver support runtime power management, the clock will be > > > disabled as soon as transfer is done. It means, on shared interrupt, we > > > will get in trouble even if there is no active transfer. > > > > The driver's runtime PM plays only with this one clock, so it seems > > you meant i2c_imx->clk. It is not this problem. > > > > > > > > So, probably the only way to fix it, is to check in i2c_imx_isr() if the > > > HW is expected to be active and register access should be save. > > > > Checking in every interrupt whether the interrupt should be serviced > > based on some SW flag because HW might be disabled? That looks unusual, > > like a hack. > > > > No, the interrupt should be registered when the driver and some other > > pieces of HW are ready to service it. > > OK. > please make sure, irq is probed before calling > i2c_add_numbered_adapter(). This will trigger deferred probing of > slave devices. Since the irq handler will be added later, tx completion > of some requests will be lost or fail. Right. I'll move the devm_request_irq(). Best regards, Krzysztof