From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: [PATCH ide] : Increase WAIT_DRQ to support slow CF cards Date: Sat, 31 Oct 2009 09:56:26 -0400 Message-ID: <4AEC420A.9030502@rtr.ca> References: <20091026162011.GA3289@frolo.macqel> <4AE64031.5060105@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:55940 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757794AbZJaN4a (ORCPT ); Sat, 31 Oct 2009 09:56:30 -0400 In-Reply-To: <4AE64031.5060105@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Robert Hancock Cc: Philippe De Muyter , linux-ide@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org Robert Hancock wrote: .. > This has come up before: > > http://marc.info/?l=linux-ide&m=123064513313466&w=2 > > I think this timeout should not even exist. libata has no such timeout > (only the overall command completion timeout), and I can't find any > reference in current ATA specs to the device being required to raise DRQ > in any particular amount of time. .. The reason for the original (20ms, then 50ms) timeout was this text from the ATA1 specification, long since outdated: - Upon receipt of a Class 3 command, the drive sets BSY within 400 nsec, sets up the sector buffer for a write operation, sets DRQ within 20 msec, and clears BSY within 400 nsec of setting DRQ. Cheers