From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: FUA and DPO unsupported using sata_nv on MCP55? Date: Mon, 09 Apr 2007 16:45:11 +0900 Message-ID: <4619EF07.5090008@gmail.com> References: <1175778811.5181.9.camel@ukabzc383.uk.saic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from wr-out-0506.google.com ([64.233.184.226]:36942 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbXDIHpT (ORCPT ); Mon, 9 Apr 2007 03:45:19 -0400 Received: by wr-out-0506.google.com with SMTP id 71so816436wri for ; Mon, 09 Apr 2007 00:45:18 -0700 (PDT) In-Reply-To: <1175778811.5181.9.camel@ukabzc383.uk.saic.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Eamonn Hamilton Cc: linux-ide@vger.kernel.org Eamonn Hamilton wrote: > Hi, > > I've got a couple of Samsung HD501LJ drives attached to a KN9 Ultra > board using the MCp55 chipset, and I'm getting an NCQ depth of 0 > reported at boot, which as I understand it is because support for NCQ > isn't in the sata_nv driver yet for this chipset. > > ata1.00: ATA-7, max UDMA7, 976773168 sectors: LBA48 NCQ (depth 0/32) > ata2.00: ATA-7, max UDMA7, 976773168 sectors: LBA48 NCQ (depth 0/32) Yeap. > Later in the boot, however, I get > SCSI device sda: write cache: enabled, read cache: enabled, doesn't > support DPO or FUA > SCSI device sda: write cache: enabled, read cache: enabled, doesn't > support DPO or FUA > > which as I understand it means my data ( plus the wifes picture > archive! ) is at risk, as I have write cache enabled and barrier support > is disabled because of the lack of FUA. Is this caused by my drives, or > is there something I need to enable? Nothing is in danger. FUA just speeds up barrier a tad bit. Doesn't matter really. -- tejun