From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH #upstream-fixes] libata: implement libata.force_cbl parameter Date: Wed, 09 Jan 2008 10:46:03 +0900 Message-ID: <4784275B.8050506@gmail.com> References: <4783786A.6040608@gmail.com> <20080108144004.30a18457@lxorguk.ukuu.org.uk> <4784213F.4070203@gmail.com> <20080109013728.3b213cfb@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from wa-out-1112.google.com ([209.85.146.178]:22435 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750720AbYAIBqO (ORCPT ); Tue, 8 Jan 2008 20:46:14 -0500 Received: by wa-out-1112.google.com with SMTP id v27so83995wah.23 for ; Tue, 08 Jan 2008 17:46:14 -0800 (PST) In-Reply-To: <20080109013728.3b213cfb@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Jeff Garzik , IDE/ATA development list Alan Cox wrote: >> This only forces PATA controllers to certain cable type. It's a last >> resort method for installation or live media - just enough to get things >> going. > > In which case we only need to be able to force UDMA33 or less ? Cable detection goes wrong and 40c is detected as 80c. However, we got (un)lucky and all PIO and short transfers succeed however when large UDMA transfer starts, the drive detects transmission error and unfortunately does the right thing - reports transmission error via check sense. libata EH currently doesn't analyze sense data and simplify passes it to sr. sr knows transmission failure occurred but there isn't much it can do. -- tejun