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=-5.6 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,USER_AGENT_SANE_1 autolearn=unavailable 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 79528C433DF for ; Mon, 15 Jun 2020 07:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 541F5206D7 for ; Mon, 15 Jun 2020 07:15:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592205350; bh=8bGiSiOFfjzQyZwWaVo0MIKKLGRRqbDVLx5nGH9Tg34=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=TrpT24bwFomcRGO4XN18qhi4KWkKnm5TGxH4qwPW8VqV8WmpshWN6ajTiZXMKAm7t IthSWQZauwbF4L2i68jQEFNQXFmG7UMeqclVWRUMkg/jkRnMM3fFpafRkG8ARNHJru UWOD280MxfEYz3xlaInUo1vMO1h8OhqZMpkXMUkA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728492AbgFOHPp (ORCPT ); Mon, 15 Jun 2020 03:15:45 -0400 Received: from mail-ej1-f68.google.com ([209.85.218.68]:45721 "EHLO mail-ej1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728285AbgFOHPo (ORCPT ); Mon, 15 Jun 2020 03:15:44 -0400 Received: by mail-ej1-f68.google.com with SMTP id o15so16222986ejm.12; Mon, 15 Jun 2020 00:15:44 -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:user-agent; bh=ezGycCaw0ibZSkNzIrgHWo9J2DFW467MFyh+xHFUz3E=; b=O6yD+qSscWe0AfixLx9UHYAYt3C4Ne+1rqLzlIwd4EpQVQrsWAGyzJAvrddu9hjIUa p7l8NPDbe80SF78zdC7Nwh/NzH0xBduJuS9sSb2XDUa3j+TcOwe/YHB4yxEGG2lOsVAW kktxKloWBfuPQ1tmSqvDNjrEh85AV1zGU8OM11RlBmBit2l8FBcInSNbHwpqG/Wvqb09 Lcd+I5rSzJ+wTgEAUp//gptCqSCvgycYEGkVUv1HedOwCXGkAmDIhC+jMXdZuGvnFKyy F6XdY/T1nEuQfqysyCHBwKek4g8Lq9QjwlWfQWeHlms1/UxLHaqoDRVGjG9kLw6gCYC9 /h5Q== X-Gm-Message-State: AOAM533syom01D5vpKpsW9mkQffOXL42f3ZCcUo0JXlh/njzzhaAnkPg xh4eYBFvVmq6LZl2qGoQV0zl1yPf X-Google-Smtp-Source: ABdhPJyACgZYA4G7jO6h9SuACk7c2pkUmuJBW+93Py4P2vGIh/O8MANjOSByTqWqt4O5P0q6434xnw== X-Received: by 2002:a17:906:3158:: with SMTP id e24mr23753833eje.543.1592205343381; Mon, 15 Jun 2020 00:15:43 -0700 (PDT) Received: from kozik-lap ([194.230.155.184]) by smtp.googlemail.com with ESMTPSA id o16sm8519215ejg.106.2020.06.15.00.15.41 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 15 Jun 2020 00:15:42 -0700 (PDT) Date: Mon, 15 Jun 2020 09:15:40 +0200 From: Krzysztof Kozlowski To: Vladimir Oltean Cc: Mark Brown , Vladimir Oltean , linux-spi , lkml , Pengutronix Kernel Team , Marc Kleine-Budde , Wolfram Sang , stable@vger.kernel.org Subject: Re: [PATCH 1/2] spi: spi-fsl-dspi: Fix external abort on interrupt in exit paths Message-ID: <20200615071540.GB20941@kozik-lap> References: <1592132154-20175-1-git-send-email-krzk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Sun, Jun 14, 2020 at 06:48:04PM +0300, Vladimir Oltean wrote: > On Sun, 14 Jun 2020 at 13:57, Krzysztof Kozlowski wrote: > > > > If interrupt comes late, during probe error path or device remove (could > > be triggered with CONFIG_DEBUG_SHIRQ), the interrupt handler > > dspi_interrupt() will access registers with the clock being disabled. This > > leads to external abort on non-linefetch on Toradex Colibri VF50 module > > (with Vybrid VF5xx): > > > > $ echo 4002d000.spi > /sys/devices/platform/soc/40000000.bus/4002d000.spi/driver/unbind > > > > Unhandled fault: external abort on non-linefetch (0x1008) at 0x8887f02c > > Internal error: : 1008 [#1] ARM > > CPU: 0 PID: 136 Comm: sh Not tainted 5.7.0-next-20200610-00009-g5c913fa0f9c5-dirty #74 > > Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree) > > (regmap_mmio_read32le) from [<8061885c>] (regmap_mmio_read+0x48/0x68) > > (regmap_mmio_read) from [<8060e3b8>] (_regmap_bus_reg_read+0x24/0x28) > > (_regmap_bus_reg_read) from [<80611c50>] (_regmap_read+0x70/0x1c0) > > (_regmap_read) from [<80611dec>] (regmap_read+0x4c/0x6c) > > (regmap_read) from [<80678ca0>] (dspi_interrupt+0x3c/0xa8) > > (dspi_interrupt) from [<8017acec>] (free_irq+0x26c/0x3cc) > > (free_irq) from [<8017dcec>] (devm_irq_release+0x1c/0x20) > > (devm_irq_release) from [<805f98ec>] (release_nodes+0x1e4/0x298) > > (release_nodes) from [<805f9ac8>] (devres_release_all+0x40/0x60) > > (devres_release_all) from [<805f5134>] (device_release_driver_internal+0x108/0x1ac) > > (device_release_driver_internal) from [<805f521c>] (device_driver_detach+0x20/0x24) > > > > The resource-managed framework should not be used for interrupt handling, > > because the resource will be released too late - after disabling clocks. > > The interrupt handler is not prepared for such case. > > > > Fixes: 349ad66c0ab0 ("spi:Add Freescale DSPI driver for Vybrid VF610 platform") > > Cc: > > Signed-off-by: Krzysztof Kozlowski > > > > --- > > I don't buy this argument that "the resource-managed framework should > not be used for interrupt handling". What is it there for, then? It was created long time ago for memory allocations and since then people ported to all other possibilities and used in drivers. Just because you can do something, does not necessarily mean that you should... > Could you just call disable_irq before clk_disable_unprepare instead > of this massive rework? This massive rework is 9 insertions and 4 deletions, indeed I made impressive, huge commit with significant impact. disable_irq() could work as well so if this is preferred, no problem from my side. Best regards, Krzysztof