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 EB33DC04A94 for ; Mon, 14 Aug 2023 07:51:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234329AbjHNHvX (ORCPT ); Mon, 14 Aug 2023 03:51:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234319AbjHNHuy (ORCPT ); Mon, 14 Aug 2023 03:50:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6D3C9F; Mon, 14 Aug 2023 00:50:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3AD75610F4; Mon, 14 Aug 2023 07:50:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B35C7C433C8; Mon, 14 Aug 2023 07:50:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691999452; bh=x3wF5vzE2q8dWA8gYzwJnJgKRnZUE1HvAzXLwGWh+nE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=W+HI9eWs+zOaoW2BnawxUEGwFa64bJC3asFINzJnN+VYd/mA74HaErxRaV43QbDj5 dltDdiaughOKS/slTxeeW/fSsofsKDEn533vDPSivSQ+3buXgtVovFwD6ewv1bmPvK +9pCuUx9E3CaedT2Xu4QVLlDxsIv+eKKWG0YVVkPXWbLUcGxjo8uQdbjrRhBAeMxge Jf/I7+fgi8R75lQKuiU7NphLuCnkypZFot53Tq0USd6V3/hsEdB0tve618QWc4N04e eEjo5NpUFet6oRQPw4CaeUTZj+rVuSQUWKmGkpGdUfHZQHTaTS2R9dtndIeehuwFsu iq39b9sYx4PTg== Message-ID: Date: Mon, 14 Aug 2023 16:50:50 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH] scsi: ata: Fix a race condition between scsi error handler and ahci interrupt Content-Language: en-US To: Li Nan Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linan122@huawei.com, yukuai3@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com References: <20230810014848.2148316-1-linan666@huaweicloud.com> <25c1aca7-d885-0fff-2639-bb68a7dff44f@kernel.org> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/14/23 15:41, Li Nan wrote: >> This is definitely not correct because EH may have been scheduled for a non >> fatal action like a device revalidate or to get sense data for successful >> commands. With this change, the port will NOT be frozen when a hard error IRQ >> comes while EH is waiting to start, that is, while EH waits for all commands to >> complete first. >> > > Yeah, we should find a better way to fix it. Do you have any suggesstions? > >> Furthermore, if you get an IRQ that requires the port to be frozen, it means >> that you had a failed command. In that case, the drive is in error state per >> ATA specs and stops all communication until a read log 10h command is issued. >> So you should never ever see 2 error IRQs one after the other. If you do, it >> very likely means that you have buggy hardware. >> >> How do you get into this situation ? What adapter and disk are you using ? >> > > > How do you get into this situation ? > The first IRQ is io error, the second IRQ is disk link flash break. What does "link flash break" mean ? > > > What adapter and disk are you using ? > It is a disk developed by our company, but we think the same issue > exists when using other disks. As I said, I find this situation highly suspect because if the first IRQ was to signal an IO error that the drive reported, then per ATA specifications, the drive should be in error mode and should NOT have transmitted any other FIS after the SDB FIS that signaled the error. Nothing at all should come after that error SDB FIS, until the host issues a read log 10h to get thee drive out of error state. If this is a prototype device, I would recommend that you take an ATA bus trace and verify the FIS traffic. Something fishy is going on with the drive in my opinion. -- Damien Le Moal Western Digital Research