From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Host protected area on suspend/resume Date: Tue, 12 Jul 2005 23:49:35 +0900 Message-ID: <42D3D87F.5040901@gmail.com> References: <20050712113044.GA8744@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from zproxy.gmail.com ([64.233.162.206]:49364 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S261504AbVGLOto (ORCPT ); Tue, 12 Jul 2005 10:49:44 -0400 Received: by zproxy.gmail.com with SMTP id m7so531214nzf for ; Tue, 12 Jul 2005 07:49:42 -0700 (PDT) In-Reply-To: <20050712113044.GA8744@srcf.ucam.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Matthew Garrett Cc: linux-ide@vger.kernel.org, B.Zolnierkiewicz@elka.pw.edu.pl Matthew Garrett wrote: > On boot, Linux will attempt to disable the host protected area on a > disk. After a suspend/resume cycle, the BIOS may reenable it (seen on a > Thinkpad T40 and R40). As a result, the kernel is now unable to access > the HPA. > > Is there any issue with just adding a call to idedisk_check_hpa() in the > IDE resume code? This has come up several times now. One thing I'm curious about is why we are disabling HPA on boot without consent from the user. AFAIK, HPA is mostly used to implement hidden recovery/suspend storage areas and disabling automatically on boot increases the likeliness of destroying them. What do we gain by disabling HPA on boot? Are there some dumb machines which unnecessarily sets HPA and reduces the capacity of drives excessively? Even in such cases, wouldn't it be better to do idedisk_check_hpa() only when kernel parameter explicitly says so? -- tejun