From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH RESEND 0/3] scsi: fix internal write cache issue on usb hdd. Date: Mon, 16 Jul 2012 16:48:05 -0700 Message-ID: <20120716234805.GA9875@kroah.com> References: <1341716685-6631-1-git-send-email-linkinjeon@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:62949 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751719Ab2GPXsK (ORCPT ); Mon, 16 Jul 2012 19:48:10 -0400 Received: by pbbrp8 with SMTP id rp8so10800388pbb.19 for ; Mon, 16 Jul 2012 16:48:10 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1341716685-6631-1-git-send-email-linkinjeon@gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Namjae Jeon Cc: James.Bottomley@HansenPartnership.com, mdharm-usb@one-eyed-alien.net, stern@rowland.harvard.edu, sshtylyov@mvista.com, bvanassche@acm.org, akpm@linux-foundation.org, linux-usb@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Namjae Jeon On Sat, Jul 07, 2012 at 11:04:45PM -0400, Namjae Jeon wrote: > From: Namjae Jeon > > The numbers of USB HDDs(All USB HDD I checked) does not respond > correctly to scsi mode sense command for retrieving the write cache > page status. Even though write cache is enabled by default, due to > scsi driver assume that cache is not enabled which in turn might lead > to loss of data since data still will be in cache. > This result that all filesystems is not stable on USB HDD when the > device is unplugged abruptly, even though these are having journaling > feature. Our first trying is that scsi driver send ATA command > (ATA Pass through, #85) to USB HDD after failure from normal routine to > know write cache enable. > We have known it is dangerous after testing several USB HDD. some of > HDD is stalled by this command(A-DATA HDD). So we tried to make the > patch James Bottomley's suggestion(usb quirk) on version 2 that add > product ID and verdor ID of USB HDD to USB quirk list after checking > write cache. > All filesystem will be stable on USB HDD registered in quirk list. > And it will be updated continuously. Now applied to the usb-next branch. thanks, greg k-h