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 2C37FC433EF for ; Tue, 30 Nov 2021 19:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238344AbhK3TgE (ORCPT ); Tue, 30 Nov 2021 14:36:04 -0500 Received: from mail-pg1-f175.google.com ([209.85.215.175]:39860 "EHLO mail-pg1-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233472AbhK3Tfq (ORCPT ); Tue, 30 Nov 2021 14:35:46 -0500 Received: by mail-pg1-f175.google.com with SMTP id r5so20878104pgi.6 for ; Tue, 30 Nov 2021 11:32:27 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=FGJHCtmg2p0jEd3C1f97Dx+Eko6wlb8p+DGE5PgWzeQ=; b=ZCpnEzMyhGp2eKdTm5hGNmS7/g8Tltnf0TFdhKz1F03D1eUfB93PNZCUxgCmkQZntY h4DNb5Dn4WJ003GrmRrsNtkAibYdrgCiT8Fc1dYepRyQ7wBnNBL57Ttx3Ispjoa2+v9m 4QgurnxF9uHkG8TGGbJ4Pqg4Ie3axfbyqzJ3uEKV72xtX9eWbKggtLZs5D+Ms2ZNn903 G2A8mjrXHsS/5Mxe0Jske+/CGzxk/8j0BCy0BHf+p9HF8oWge83ilXiDvY0xFzWFoJAz WDl/A7F5CMgN3OLpFvS32uMfv6EqQTX/BIfeDskGTh9TsNjyzkD2FHmbYFLK3J+FT//L sfvA== X-Gm-Message-State: AOAM533ipktBDS+A2oQwmLpgJZYsZX93B8WNH6lAoapAnSzDsztigpRg FLxUvlteqOAgcYEgxU5AkyM= X-Google-Smtp-Source: ABdhPJxUBTM6+euupcIWF+QGrDAYeUXG2M63d3uyGalLzLTgZZsiN7vaP/Lg4lpbMC0Hszz/4HCzpw== X-Received: by 2002:a05:6a00:1693:b0:44c:64a3:d318 with SMTP id k19-20020a056a00169300b0044c64a3d318mr886788pfc.81.1638300747061; Tue, 30 Nov 2021 11:32:27 -0800 (PST) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:ef1f:f086:d1ba:8190]) by smtp.gmail.com with ESMTPSA id na13sm3795225pjb.11.2021.11.30.11.32.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Nov 2021 11:32:26 -0800 (PST) Subject: Re: [PATCH v2 13/20] scsi: ufs: Fix a deadlock in the error handler To: Bean Huo , "Martin K . Petersen" Cc: Jaegeuk Kim , Adrian Hunter , linux-scsi@vger.kernel.org, "James E.J. Bottomley" , Bean Huo , Can Guo , Avri Altman , Stanley Chu , Asutosh Das References: <20211119195743.2817-1-bvanassche@acm.org> <20211119195743.2817-14-bvanassche@acm.org> <788d060573ed475a902f17bc32d05540b78e66da.camel@gmail.com> From: Bart Van Assche Message-ID: <235fe40e-5695-a7a6-7422-68fc6d33cdac@acm.org> Date: Tue, 30 Nov 2021 11:32:25 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <788d060573ed475a902f17bc32d05540b78e66da.camel@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 11/30/21 12:54 AM, Bean Huo wrote: > We are looking for alternative > methods: for example, to fix this problem from the SCSI layer; > Add a new dedicated hardware device management queue on the UFS device > side. Hi Bean, I don't think that there are any alternatives. If all host controller tags are in use, it is not possible to implement a mechanism in software to create an additional tag. Additionally, stealing a tag is not possible since no new request can be submitted to a UFS controller if all tags are in use. Thanks, Bart.