From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 02/02] sata_mv: warn on PIO with multiple DRQs Date: Thu, 19 Jun 2008 10:48:47 +0900 Message-ID: <4859BAFF.1060800@gmail.com> References: <485933A4.3010409@rtr.ca> <4859340E.60203@rtr.ca> <4859A886.8000509@pobox.com> <4859B9E2.4060909@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ti-out-0910.google.com ([209.85.142.191]:44271 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751821AbYFSBsx (ORCPT ); Wed, 18 Jun 2008 21:48:53 -0400 Received: by ti-out-0910.google.com with SMTP id b6so219416tic.23 for ; Wed, 18 Jun 2008 18:48:51 -0700 (PDT) In-Reply-To: <4859B9E2.4060909@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: Jeff Garzik , IDE/ATA development list Mark Lord wrote: >>> We may also want a patch to prevent libata-eh from downshifting >>> all the way to PIO on these chipsets, but I am not sure how to >>> accomplish that from inside sata_mv. Any suggestions? >> >> Do we really want that? Seems to me we need that for older bridged >> PATA devices attached to a SATA bridge. > .. > > Just about everything can do some form of DMA nowadays, > but regardless of that the sata_mv chipsets have errata > for PIO of anything more than a single sector. > > In practice, I haven't managed to trigger the issue here, > but the errata descriptions indicate that it should be a major > issue for any volume of multi-sector PIO commands. The following nack'd patch has something similar if it's really necessary. http://article.gmane.org/gmane.linux.ide/32282 -- tejun