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 BE691C77B7D for ; Sun, 7 May 2023 15:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231219AbjEGPDH (ORCPT ); Sun, 7 May 2023 11:03:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230356AbjEGPDG (ORCPT ); Sun, 7 May 2023 11:03:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3298B7EF5; Sun, 7 May 2023 08:03:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B935560E09; Sun, 7 May 2023 15:03:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12C08C433EF; Sun, 7 May 2023 15:03:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683471784; bh=tyMJVdXEq4oCoHCPYlSJKEY5GmMz0MTWHInscNM+1lk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=H6dE5fi1rymlSBMXaQgjrnyB6XL8gL1nhUcKsuTdU+L738FJFQwmr0jep1lWcJ9ce LV8XZLoxoyfZ+WwCbWZem7y7gk4vX9QNSE1dwN1SU96xEpHS8vtOb0nCOEAo5mczHx l4P9rKuo6xMl2PmsmZSj8Mv00zwGGEpOjteA7Yg5WHVSGZyBlvkWUfVm72417pnhV5 opArf7LoWpdQ2N30BQEufwt7A3e10Rn5DmqHa/u9winMRQNGw/98rINJZtB5JSSHfp wtsfqUH/BZWFKxaPkbQZeypjX2R+KbhOHMgv8VielJaU3qkVUJaRZy2Fdjj2jf/7/9 9mjUni4tRpVXQ== Message-ID: <087b77f8-3ff2-87ce-d197-e238b8ad9047@kernel.org> Date: Mon, 8 May 2023 00:02:59 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v2] ata: libata-scsi: Fix get identity data failed Content-Language: en-US To: John Garry , yangxingui , jejb@linux.ibm.com, martin.petersen@oracle.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, prime.zeng@hisilicon.com, kangfenglong@huawei.com References: <20230505025712.19438-1-yangxingui@huawei.com> <291f1d97-9195-45ac-8e12-058f5c797277@kernel.org> <1b703656-e966-63f8-19dd-33e4e9914676@huawei.com> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2023/05/05 18:51, John Garry wrote: > On 05/05/2023 10:14, yangxingui wrote: >>> hmmm... is it really acceptable that libata is referencing libsas? I >>> didn't think that it would be. libsas uses libata, not the other way >>> around. >> Yeah, I didn't expect that either. Is there any other way? If so, is >> patch v1 OK? > > I still think that we can do better than v1. > >>> >>>>>   #include >>>>>   #include >>>>>   #include >>>>> @@ -2745,10 +2746,17 @@ static struct ata_device >>>>> *__ata_scsi_find_dev(struct ata_port *ap, >>>>>    *    Associated ATA device, or %NULL if not found. >>>>>    */ >>>>>   struct ata_device * >>>>> -ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device >>>>> *scsidev) >>>> Why drop the const ? >>>> >>>>> +ata_scsi_find_dev(struct ata_port *ap, struct scsi_device *scsidev) >>>>>   { >>>>> -    struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev); >>>>> +    struct ata_device *dev; >>>>> + >>>>> +    if (ap->flags & ATA_FLAG_SAS_HOST) { >>> >>> And this is SAS host. Not necessarily libsas (even though with ipr >>> libata usage gone, it would be the only user). >> Add a new flag only for libsas? > > No, because of previous reason. > > Please remind me - at what point do we error within ata_scsi_find_dev() > and return NULL for a libsas host? > > Note: it would be good to include that commit message for future reference. > > Maybe we could add a method to ata_port_operations to do this lookup. I > assume that is abusing ata_port_operations purpose, since it's mostly > for HW methods. > > Or do we actually use sdev->hostdata for libata or libsas? If not, maybe > we could store the struct ata_device pointer there. > > I'm just thinking out loud now... Agree. Ideally, libasas should not be any different than a for a drive used with ahci/sata/pata adapters. After all, all of them are scsi devices as well. So we need to understand why this happens only with libsas and correct the device setup there. -- Damien Le Moal Western Digital Research