From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932353AbVHKUyu (ORCPT ); Thu, 11 Aug 2005 16:54:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932452AbVHKUyu (ORCPT ); Thu, 11 Aug 2005 16:54:50 -0400 Received: from mail.dvmed.net ([216.237.124.58]:49320 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932353AbVHKUyt (ORCPT ); Thu, 11 Aug 2005 16:54:49 -0400 Message-ID: <42FBBB10.9020407@pobox.com> Date: Thu, 11 Aug 2005 16:54:40 -0400 From: Jeff Garzik User-Agent: Mozilla Thunderbird 1.0.6-1.1.fc4 (X11/20050720) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "linux-ide@vger.kernel.org" CC: Linux Kernel , Bartlomiej Zolnierkiewicz , Alan Cox , Mark Lord Subject: libata PATA todo list Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: 0.5 (/) X-Spam-Report: Spam detection software, running on the system "srv2.dvmed.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Since there's been some recent interest in the subject, I thought I would post the PATA todo list for libata. Some of these items are from my memory, and some are from a list Alan was kind enough to create. The items verbatim from Alan are prefixed "Alan: ". [...] Content analysis details: (0.5 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.5 TO_ADDRESS_EQ_REAL To: repeats address as real name Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Since there's been some recent interest in the subject, I thought I would post the PATA todo list for libata. Some of these items are from my memory, and some are from a list Alan was kind enough to create. The items verbatim from Alan are prefixed "Alan: ". 1) Locked device/host speed To support devices such as those in the ide/pci/generic.c list, we need to ensure that libata -never- attempts to change the device speed (ata_dev_set_xfermode should be avoided). 2) Simplex DMA PCI IDE specification has a 'simplex' DMA bit, which should be tested. Simplex means that only one command can be outstanding, for BOTH port0 and port1, at any given time. Possibly some hosts also need Simplex DMA, but may not assert the standard PCI IDE Simplex DMA capability bit. I don't know. 3) Speed change on error Downshift device to a slower UDMA speed, and eventually from DMA->PIO, as errors persist. There is no 'specified way' to do this, this is purely hueristic. 4) Alan: Command filter Alan -- explanation? I know one line item here, at least: Promise controllers snoop SET FEATURES - XFER MODE command. We must stop command processing on ALL ports when this command is issued, to avoid corruption. 5) Alan: MWDMA broken still? is piix doc correct? 6) Alan: some PATA LBA48 devices cannot do > 256 sectors. 7) Alan: Some ALi requires LBA48 be done via PIO. LBA28 DMA is OK. 8) ATAPI device CDB interrupt Some older ATAPI devices require the OS driver to wait for an interrupt, after CDB is written, before command processing proceeds. 9) ATAPI devices may delay setting DRQ=1 for up to 3ms. Make sure we honor the delay noted in IDENTIFY PACKET DEVICE word 0. 10) ATAPI DMA alignment (discussed elsewhere) Needed even for PATA, AFAICT.