Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756782AbZDSUMV (ORCPT ); Sun, 19 Apr 2009 16:12:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754762AbZDSUMM (ORCPT ); Sun, 19 Apr 2009 16:12:12 -0400 Received: from smtp.flash.net.br ([201.46.240.48]:46289 "EHLO smtp.gru.flash.tv.br" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754732AbZDSUML (ORCPT ); Sun, 19 Apr 2009 16:12:11 -0400 Date: Sun, 19 Apr 2009 17:11:32 -0300 From: =?utf-8?Q?Rog=C3=A9rio?= Brito To: Jeff Garzik Cc: Michael Tokarev , Mark Lord , linux-kernel@vger.kernel.org Subject: Re: Quick question about libata and hdparm Message-ID: <20090419201132.GB2891@ime.usp.br> References: <49EB1A33.7050808@rtr.ca> <49EB1C9C.3000105@msgid.tls.msk.ru> <49EB1FB3.5000609@garzik.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <49EB1FB3.5000609@garzik.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1304 Lines: 34 Hi, Jeff. On Apr 19 2009, Jeff Garzik wrote: > Michael Tokarev wrote: >> Well, the kernel does a good job here in *almost* all cases. >> The problematic case is when a device has some bad/unreadable >> blocks/sectors. When such a place occurs on read, libata >> (or whatever it is) performs several retries, each time >> using "less aggressive" settings - like reducing UDMA and >> PIO mode till the lowest possible PIO/33. And the device >> stays in that mode until reboot, even if the problematic >> sector has been relocated. So it'd be nice to be able to >> reset the mode back in such cases. > > Do you have a log? I have a log here of libata reducing UDMA speed. I don't know if this is any hardware problem or not (I think not), but I do see libata complaining and reducing the speed of the drive. Would you like it? Thanks, -- Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8 http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/