From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [linux-usb-devel] question on flushing buffers and spinning down disk Date: Mon, 24 Sep 2007 22:00:03 +0200 Message-ID: <200709242200.04278.oliver@neukum.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp-out001.kontent.com ([81.88.40.215]:36517 "EHLO smtp-out.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753614AbXIXT7M convert rfc822-to-8bit (ORCPT ); Mon, 24 Sep 2007 15:59:12 -0400 In-Reply-To: Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Alan Stern Cc: linux-usb-devel@lists.sourceforge.net, James Bottomley , linux-scsi@vger.kernel.org Am Montag 24 September 2007 schrieb Alan Stern: > On Mon, 24 Sep 2007, Oliver Neukum wrote: >=20 > > > subsystem implements its own form of runtime PM support, then you= 'll be > > > able to use it properly. =A0But until then, there isn't anything = much you > > > can do. > >=20 > > Well, we can't simply cut power. Buffers must be flushed and the di= sk > > spun down. The suspend() method of the storage driver will have to = become > > complex. >=20 > That's right, if the device is a real disk. =A0If it's a flash memory > device then of course these issues don't arise. =A0Unfortunately the > driver isn't able to tell one from the other; the user will have to > do that for us. So those devices which draw most power we don't suspend :-( =46urthermore for many devices it will take real user intervention to determine what is in the enclosure. This isn't very good. I think we can do better. Regards Oliver - To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html