From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [usb-storage] Re: Fwd: 2TB USB hard drive for backing up Date: Tue, 22 Jan 2013 13:17:20 -0600 Message-ID: <2d90dddf-1bdc-4f43-bdf3-9ec09e38bb8b@email.android.com> References: <50FEC6D6.3030708@zytor.com> <1358874830.2387.46.camel@dabdike.int.hansenpartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <1358874830.2387.46.camel-sFMDBYUN5F8GjUHQrlYNx2Wm91YjaHnnhRte9Li2A+AAvxtiuMwx3w@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: James Bottomley Cc: Alan Stern , Oliver Neukum , Ellwood Blues , linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi , USB Storage List List-Id: linux-scsi@vger.kernel.org Don't worry... I have lived in that world for decades... it's a lot like BIOS. James Bottomley wrote: >On Tue, 2013-01-22 at 11:05 -0600, H. Peter Anvin wrote: >> On 01/22/2013 09:43 AM, Alan Stern wrote: >> > On Tue, 22 Jan 2013, Oliver Neukum wrote: >> > >> >> On Tuesday 22 January 2013 11:05:35 James Bottomley wrote: >> >>>> May 3 18:19:06 relampago3 kernel: [ 3948.472796] sd 7:0:0:0: >[sdf] >> >>>> 1565565872 512-byte logical blocks: (801 GB/746 GiB) >> >>> >> >>> This looks like a wrap around of your actual size. This appears >to >> >>> indicate the device isn't replying correctly to READ CAPACITY. >The >> >>> conventional return from READ CAPACITY should be -1 which would >trigger >> >>> us to retry with READ CAPACITY(16). >> >> >> >> What can we do? The answer the device is giving is quite ordinary. >> >> Do we need another quirk and an associated flag? >> > >> > The JMicron bridges are well known to be fairly buggy. Another >quirk >> > may indeed be the only solution. Oliver, would you like to write a > >> > patch for it? >> > >> >> Would it make more sense to try READ CAPACITY(16) first? Or does >that >> have other bad effects? > >That has other effect: Many USB devices crash the firmware on 16 byte >commands (sigh, welcome to our world ...) > >James -- Sent from my mobile phone. Please excuse brevity and lack of formatting.