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 A0961C77B73 for ; Mon, 22 May 2023 07:05:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230210AbjEVHFv (ORCPT ); Mon, 22 May 2023 03:05:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231220AbjEVHFV (ORCPT ); Mon, 22 May 2023 03:05:21 -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 BB4C61FEF; Mon, 22 May 2023 00:02:20 -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 C6A1361197; Mon, 22 May 2023 07:02:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36A79C433EF; Mon, 22 May 2023 07:02:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684738938; bh=c4gWqr9ur4of/a8IC06iYHE7k0Seduk+Q9U0csTEnpE=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=CDrbZwdhAf88j9UkLMmkDgcaPt//jDinfRmwjncBfzJMJ+kHL005fLuLGd6rBqEkw kbHokEnu3u1GdDnkLzmDhpxEd/TVL3hiWSoZzjrS/I45qGySLF0xMJEXWLiMYDxrZs ERkJ0gDAK3RtCEjYOzHK1Qr9XEtkC8g5vpHR0AX9RnMFhx3dCdl6z3AcarqMXhY6TX 9cq2x0c7WHJqJkr5t5CDZhZkvroPfJAL5cbVFtUuZ2jqqj6YBPSeiIj2N+Z1TAUOOH 59kCOrU/jIp+mXj6nAZK8AlY8M3426500PEb52Xbiaym0QCFV5DmDe2NmjXLyVYX9H jZ/b4mthmEejw== Message-ID: <68953040-1622-254b-f6f8-b279eccacfb1@kernel.org> Date: Mon, 22 May 2023 16:02:16 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; 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 From: Damien Le Moal To: yangxingui , jejb@linux.ibm.com, martin.petersen@oracle.com, john.g.garry@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> <02d36ee9-cdad-454d-d822-95442d7bd67b@huawei.com> <938d6b5b-0271-977d-f046-5fd70d29b3ca@huawei.com> 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 5/22/23 10:35, Damien Le Moal wrote: > On 5/8/23 10:11, yangxingui wrote: >> >> >> On 2023/5/7 22:51, Damien Le Moal wrote: >>> On 2023/05/05 18:06, yangxingui wrote: >>>> >>>> >>>> On 2023/5/5 16:17, Damien Le Moal wrote: >>>>> On 2023/05/05 11:57, Xingui Yang wrote: >>>>>> The function ata_get_identity() uses the helper ata_scsi_find_dev() to get >>>>>> the ata_device structure of a scsi device. However, when the ata device is >>>>>> managed by libsas, ata_scsi_find_dev() returns NULL, turning >>>>>> ata_get_identity() into a nop and always returns -ENOMSG. >>>>> >>>>> What do you do to hit the issue ? A while back for me it was the queue depth >>>>> setting causing problems. As Garry mentioned, this led to patch 141f3d6256e5 >>>>> ("ata: libata-sata: Fix device queue depth control"). >>>> Attempt to return the correct value at ata_scsi_find_dev() instead of >>>> NULL, when the ata device is managed by libsas? >>> >>> That I understand. My question is *what* user operation/command triggers this ? >>> Because on my test setup, under normal use, I do not see this issue (beside what >>> was already corrected with the queue depth control). Is the issue showing up >>> when using passthrough commands only ? >> Yeah, we found that command "hdparm -i /dev/sdc" always return faild for >> SATA HDD disk. as follows: >> [root@localhost ~]# hdparm -i /dev/sdc >> >> /dev/sdc: >> HDIO_GET_IDENTITY failed: Invalid argument > > I cannot recreate this issue exactly like this. Here is my setup with a pm80xx > driver (Adaptec HBA): > > [7:0:0:0] disk ATA WDC WUH721818AL W232 /dev/sdd /dev/sg5 > [7:0:1:0] disk ATA WDC WUH721818AL WTW2 /dev/sdi /dev/sg6 > [7:0:2:0] disk ATA WDC WUH722222AL Wf86 /dev/sdf /dev/sg7 > [7:0:3:0] zbc ATA WDC WSH722020AL W803 /dev/sdg /dev/sg8 > > Using the first drive, I get: > > sudo hdparm -i /dev/sdd > > /dev/sdd: > > Model=WDC WUH721818ALN604, FwRev=PCGNW232, SerialNo=3KG10LBK > Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=56 > BuffType=DualPortCache, BuffSize=unknown, MaxMultSect=2, MultSect=off > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=4394582016 > IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} > PIO modes: pio0 pio1 pio2 pio3 pio4 > DMA modes: mdma0 mdma1 mdma2 > UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 > AdvancedPM=yes: disabled (255) WriteCache=enabled > Drive conforms to: unknown: ATA/ATAPI-2,3,4,5,6,7 > > * signifies the current active mode > > So all good. However, for the following drives, I get: > > sudo hdparm -i /dev/sdi > > /dev/sdi: > HDIO_GET_IDENTITY failed: No message of desired type > > (same for sdf and sdg). > > Will dig into this. OK, so the issue is that __ata_scsi_find_dev() calls ata_find_dev() with devno == scsidev->id. This leads to devno being 0, 1, 2 and 3 for connected drives sdd, sd1, sdf and sdg, as shown by lsscsi. However, each drive has its own port+link, with the link for each one having ata_link_max_devices() == 1, so ata_find_dev() works only for the first drive with scsidev->id == 0 and fails for the others. A naive fix would be this: diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 7bb12deab70c..e4d6f17d7ccc 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2718,7 +2718,7 @@ static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap, if (!sata_pmp_attached(ap)) { if (unlikely(scsidev->channel || scsidev->lun)) return NULL; - devno = scsidev->id; + devno = 0; } else { if (unlikely(scsidev->id || scsidev->lun)) return NULL; And running this on my setup, it works. This makes libsas added ports/devices look like AHCI ones, where all devices have ID 0 for the !pmp case. However, I am not sure this would be OK for all setups... John, Any idea if there is any cases where libsas managed drives would endup not being correctly identified by this change ? As long as a device always has its own port, I do not see any issue. But is there a case where we could have multiple devices on the same port ? Per libata, max is 2, and that is only for the IDE master/slave case. Otherwise, it is always 1. Not that looking at the pmp case, I am not confident at all that the identification is correct for libsas. But I do not think that anyone would ever connect a pmp box to a libsas HBA... -- Damien Le Moal Western Digital Research