From mboxrd@z Thu Jan 1 00:00:00 1970 From: Norman Diamond Subject: Re: Large disk drives Date: Sat, 8 Nov 2014 09:35:47 +0900 (JST) Message-ID: <273787.22163.qm@web100014.mail.kks.yahoo.co.jp> References: <533357.25557.qm@web100006.mail.kks.yahoo.co.jp> <063D6719AE5E284EB5DD2968C1650D6D1C9EAE8F@AcuExch.aculab.com> Reply-To: Norman Diamond Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from web100014.mail.kks.yahoo.co.jp ([114.111.98.188]:44294 "HELO web100014.mail.kks.yahoo.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752315AbaKHAfu convert rfc822-to-8bit (ORCPT ); Fri, 7 Nov 2014 19:35:50 -0500 In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1C9EAE8F@AcuExch.aculab.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: David Laight , "linux-scsi@vger.kernel.org" , "linux-usb@vger.kernel.org" =46rom: David Laight >=20 > From: Norman Diamond > ... >> By the way, I've seen some USB bridges that lie about whether they >> performed various SAT commands (ATA passthrough), but told the trut= h >> about performing an ATA IDENTIFY DEVICE through SAT.=A0 So we could= attempt >> ATA passthrough with an IDENTIFY DEVICE command, and if it happens = to >> return a sane looking result, we could comparre it to the bridge's = own >> translation of READ_CAPACITY_10 and READ_CAPACITY_16.=A0 If the pas= sthrough >> yielded a sane result and the capacity doesn't match, we know not t= o >> trust the bridge with 16-byte commands (except if tested, as mentio= ned). >> In such a case, we don't even have to look at the partition table.=A0= Of >> course if the ATA passthrough fails or if the result is garbage the= n >> abandon this test and maybe look at the partition table. > ... >=20 > Don't count on devices answering ATA IDENTIFY correctly either. =A0 Of course.=A0 That's why you quoted me saying this: =A0 >> Of >> course if the ATA passthrough fails or if the result is garbage the= n >> abandon this test and maybe look at the partition table.=20 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html