From nobody Sun Dec 10 03:44:54 2023 X-Original-To: scsi@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SnrP33K0Tz53yYc for ; Sun, 10 Dec 2023 03:45:11 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4SnrP23PSrz3L7Q for ; Sun, 10 Dec 2023 03:45:10 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bsdimp-com.20230601.gappssmtp.com header.s=20230601 header.b="pWH/nn2A"; spf=none (mx1.freebsd.org: domain of wlosh@bsdimp.com has no SPF policy when checking 2a00:1450:4864:20::134) smtp.mailfrom=wlosh@bsdimp.com; dmarc=none Received: by mail-lf1-x134.google.com with SMTP id 2adb3069b0e04-50bfe99b6edso3996022e87.1 for ; Sat, 09 Dec 2023 19:45:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20230601.gappssmtp.com; s=20230601; t=1702179906; x=1702784706; darn=freebsd.org; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=zvtpaOW8q3hQqDj3yNrU/0EDfQ0ke4lmnQ6T3sbrtXA=; b=pWH/nn2AHxOSMixPnPRvqMlYteLbAlKYG4HHNWRqn5AM7zyR5HGJBlc7dmDgmugtVq CdR2kCakgVvQCMjnDT3t1X/IHI8uhUntXZlAyA3CNc+0aGDE1mkHaPAgs98lSPAdZtsj aNXQDUaD4dJFnzLhN+oOpVheNmeTr1UVUmKt2mURCBBfwXPa9QVh/usTBrS86p5PkuYV tKIiPaCjwldhZZFkbSHSdNKE+1NEB5q9JxCiQloNDbqBpvV7MghSkq1UfvFL423+mahT ovGRsVCaJ5pNSo8iTpt4x6VzRIazYIg7qvrmfT/jJjG+S/+Y28PpH0R/jeE2RghOgszQ j6uA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702179906; x=1702784706; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=zvtpaOW8q3hQqDj3yNrU/0EDfQ0ke4lmnQ6T3sbrtXA=; b=iysgyeJA4xlI36sEAf5cbXJBcXphgLy7crcHMiQNRVPZNr57YgiwX7Uztvv59DTgG3 rDseUuExbYDTeqpk2Khcgx5B1FwykQ3ZUifRCQPvld0Yv+LXEdjf/yQgnNmiS1IbSmGf 42HASN4KRXyQMKfEM9nUAoms3OAaJkM/zqNwLHaMOAy0/jeoltwqyGYTlrye0A7VrrEW +jM/oSx34uhU57sKojPMIsnUvMgPbBvhNy/K/rft9MdWJDMcB75BwAItLLJKPFZ+qCaK 6VGDMiCAgNx7sOXQPeweLvDJd2WnTQUYsN+txILdJv/d3eGEHJhQaH5NYbzTydaXiN4M 1Qeg== X-Gm-Message-State: AOJu0YxFYejJpAIrVp/ZxIgBmemDda/NGkfUylfKXAu9L+ViqJBQPf0i X8tfBHgU1aHs7yfe8pNV7rAACimA/8MAK6vlYLTacMfx7R5YHUM3 X-Google-Smtp-Source: AGHT+IEWBN5cba+8ai9Mf4SyWesi8R6/2iGW6WB4mijmfLw5IhkKP1bxFMPho1Mdmd2+8lrZcK8qemmKEH6xRmpL7eQ= X-Received: by 2002:ac2:5584:0:b0:50c:10b5:1744 with SMTP id v4-20020ac25584000000b0050c10b51744mr969102lfg.111.1702179905807; Sat, 09 Dec 2023 19:45:05 -0800 (PST) List-Id: SCSI subsystem List-Archive: https://lists.freebsd.org/archives/freebsd-scsi List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-scsi@freebsd.org X-BeenThere: freebsd-scsi@freebsd.org MIME-Version: 1.0 From: Warner Losh Date: Sat, 9 Dec 2023 20:44:54 -0700 Message-ID: Subject: Drop READ(6) / WRITE(6) support in da/cd To: scsi@freebsd.org Content-Type: multipart/alternative; boundary="000000000000a13fc9060c1fa4df" X-Spamd-Result: default: False [-2.94 / 15.00]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.94)[-0.937]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20230601.gappssmtp.com:s=20230601]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::134:from]; MLMMJ_DEST(0.00)[scsi@freebsd.org]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RCVD_COUNT_ONE(0.00)[1]; R_SPF_NA(0.00)[no SPF record]; RCVD_TLS_LAST(0.00)[]; ARC_NA(0.00)[]; DMARC_NA(0.00)[bsdimp.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_TRACE(0.00)[bsdimp-com.20230601.gappssmtp.com:+]; PREVIOUSLY_DELIVERED(0.00)[scsi@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; TO_DN_NONE(0.00)[]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com] X-Rspamd-Queue-Id: 4SnrP23PSrz3L7Q X-Spamd-Bar: -- --000000000000a13fc9060c1fa4df Content-Type: text/plain; charset="UTF-8" I'd like to move the default CDB size in the da driver from 6 to 10. I'd like to make the driver never send READ6 commands (and likely the cd driver too). READ10 was an extended command in X.131-1986 (SCSI-1) required for any computer with self configuring software. It became mandatory in X.131-1994 (SCSI-2), 4 years before CAM entered the tree. It's been required for any device larger than 2GB. We purposely disable it on all USB and Firewire attached devices. Its support has been strongly encouraged as an alternative to READ6 since SBC (1997), with threats to withdraw READ6 once certain system software had been updated. It became obsolete in SBC-4 (2019).The days of minimizing a couple of bytes in the CDB have long since passed. We have a lot of quirks to disable these commands for both da and cd (as well as blanket disabling them for RBC devices). In short, it's a lot of hassle that we go to, and there doesn't seem like there's any benefit. A quick search of the mailing list shows the overwhelming majority of traffic are the problems it causes. I can find no place where the benefits of using it are explained (though maybe I missed something). So, I'd like to remove it before 15, making 10 the minimum CDB for I/O commands (READ/WRITE,etc). we'll still send 6 byte commands for TEST UNIT READ, MODE SENSE, etc. While, as luck would have it, I still have some 100MB and 200MB drives, I have not HBA that has the right kind of interconnect to read them, so I can't even experiment to see if these old MAXTOR drives from the 80s support READ10... Comments? Warner --000000000000a13fc9060c1fa4df Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I'd like to move the default CDB size in the da d= river from 6 to 10. I'd like to make the driver never send READ6 comman= ds (and likely the cd driver too).

READ10 was an e= xtended command in X.131-1986 (SCSI-1) required for any computer with self = configuring software. It became mandatory in X.131-1994 (SCSI-2), 4 years b= efore CAM entered the tree. It's been required for any device larger th= an 2GB. We purposely disable it on all USB and Firewire attached devices. I= ts support has been strongly encouraged as an alternative to READ6 since SB= C (1997), with threats to withdraw READ6 once certain system software had b= een updated. It became obsolete in SBC-4 (2019).The days of minimizing a co= uple of bytes in the CDB have long since passed. We have a lot of quirks to= disable these commands for both da and cd (as well as blanket disabling th= em for RBC devices).

In short, it's a lot of h= assle that we go to, and there doesn't seem like there's any benefi= t. A quick search of the mailing list shows the overwhelming majority of tr= affic are the problems it causes. I can find no place where the benefits of= using it are explained (though maybe I missed something).
So, I'd like to remove it before 15, making 10 the minimum= CDB for I/O commands (READ/WRITE,etc). we'll still send 6 byte command= s for TEST UNIT READ, MODE SENSE, etc.

While,= as luck would have it, I still have some 100MB and 200MB drives, I have no= t HBA that has the right kind of interconnect to read them, so I can't = even experiment to see if these old MAXTOR drives from the 80s support READ= 10...

Comments?

= Warner
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