From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?B?Um9ow6Fy?= Subject: Re: Advanced Format SAT devices show incorrect physical block size Date: Wed, 11 Jan 2017 14:33:17 +0100 Message-ID: <20170111133317.GA31565@pali> References: <1484086345.2518.9.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-wj0-f196.google.com ([209.85.210.196]:34948 "EHLO mail-wj0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932177AbdAKNdZ (ORCPT ); Wed, 11 Jan 2017 08:33:25 -0500 Content-Disposition: inline In-Reply-To: <1484086345.2518.9.camel@HansenPartnership.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Alan Stern , Dainius =?utf-8?Q?Masili=C5=ABnas?= , SCSI development list , USB list , Tom Yan On Tuesday 10 January 2017 14:12:25 James Bottomley wrote: > On Tue, 2017-01-10 at 16:00 -0500, Alan Stern wrote: > > In theory, I suppose we could change the kernel so that it would > > default to READ CAPACITY(16) for devices that report a SCSI level >= > > 3, or something along those lines. In general we hesitate to make > > changes of this sort, because they almost always end up breaking > > _some_ devices -- and if that happens then the change is reverted, > > with no exceptions. Linus has a very strict rule about not breaking > > working systems. > > You shouldn't have to change anything: it already does (otherwise how > else would we detect physical exponent for proper SCSI devices) see > sd.c:sd_try_rc16_first(). It always returns false for USB because you > set sdev->try_rc_10_first So.. what does it mean? Can we enable READ CAPACITY(16) for some USB devices? -- Pali Rohár pali.rohar@gmail.com