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Commit 204f47c5 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz
Browse files

ide: remove stale comments from ide-dma.c (take 2) 



- ide-dma.c is not a separate module

- ide-dma.c is not PCI specific anymore

- DMA is enabled by default nowadays

- link for Intel Zappa BIOS is dead

etc.

v2:
* Some comments should be preserved. (Noticed by Mark Lord)

Cc: Mark Lord <liml@rtr.ca>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 56467d17

drivers/ide/ide-dma.c

+4 −48
Original line number Diff line number Diff line 
/*

 *  IDE DMA support (including IDE PCI BM-DMA).

 *

 *  Copyright (C) 1995-1998   Mark Lord

 *  Copyright (C) 1999-2000   Andre Hedrick <andre@linux-ide.org>

 *  Copyright (C) 2004, 2007  Bartlomiej Zolnierkiewicz

 *

 *  May be copied or modified under the terms of the GNU General Public License

 *

 *  DMA is supported for all IDE devices (disk drives, cdroms, tapes, floppies).

 */



/*
@@ -11,49 +15,6 @@ 
 */



/*

 * This module provides support for the bus-master IDE DMA functions

 * of various PCI chipsets, including the Intel PIIX (i82371FB for

 * the 430 FX chipset), the PIIX3 (i82371SB for the 430 HX/VX and 

 * 440 chipsets), and the PIIX4 (i82371AB for the 430 TX chipset)

 * ("PIIX" stands for "PCI ISA IDE Xcellerator").

 *

 * Pretty much the same code works for other IDE PCI bus-mastering chipsets.

 *

 * DMA is supported for all IDE devices (disk drives, cdroms, tapes, floppies).

 *

 * By default, DMA support is prepared for use, but is currently enabled only

 * for drives which already have DMA enabled (UltraDMA or mode 2 multi/single),

 * or which are recognized as "good" (see table below).  Drives with only mode0

 * or mode1 (multi/single) DMA should also work with this chipset/driver

 * (eg. MC2112A) but are not enabled by default.

 *

 * Use "hdparm -i" to view modes supported by a given drive.

 *

 * The hdparm-3.5 (or later) utility can be used for manually enabling/disabling

 * DMA support, but must be (re-)compiled against this kernel version or later.

 *

 * To enable DMA, use "hdparm -d1 /dev/hd?" on a per-drive basis after booting.

 * If problems arise, ide.c will disable DMA operation after a few retries.

 * This error recovery mechanism works and has been extremely well exercised.

 *

 * IDE drives, depending on their vintage, may support several different modes

 * of DMA operation.  The boot-time modes are indicated with a "*" in

 * the "hdparm -i" listing, and can be changed with *knowledgeable* use of

 * the "hdparm -X" feature.  There is seldom a need to do this, as drives

 * normally power-up with their "best" PIO/DMA modes enabled.

 *

 * Testing has been done with a rather extensive number of drives,

 * with Quantum & Western Digital models generally outperforming the pack,

 * and Fujitsu & Conner (and some Seagate which are really Conner) drives

 * showing more lackluster throughput.

 *

 * Keep an eye on /var/adm/messages for "DMA disabled" messages.

 *

 * Some people have reported trouble with Intel Zappa motherboards.

 * This can be fixed by upgrading the AMI BIOS to version 1.00.04.BS0,

 * available from ftp://ftp.intel.com/pub/bios/10004bs0.exe

 * (thanks to Glen Morrell <glen@spin.Stanford.edu> for researching this).

 *

 * Thanks to "Christopher J. Reimer" <reimer@doe.carleton.ca> for

 * fixing the problem with the BIOS on some Acer motherboards.

 *
@@ -65,11 +26,6 @@ 
 *

 * Most importantly, thanks to Robert Bringman <rob@mars.trion.com>

 * for supplying a Promise UDMA board & WD UDMA drive for this work!

 *

 * And, yes, Intel Zappa boards really *do* use both PIIX IDE ports.

 *

 * ATA-66/100 and recovery functions, I forgot the rest......

 *

 */



#include <linux/module.h>