Subject: [PATCH] ide: remove stale comments from ide-dma.c

- 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.

Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
---
drivers/ide/ide-dma.c | 48 ------------------------------------------------
1 file changed, 48 deletions(-)

Index: b/drivers/ide/ide-dma.c
===================================================================
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -11,49 +11,6 @@
*/

/*
- * 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 <[email protected]> for researching this).
- *
* Thanks to "Christopher J. Reimer" <[email protected]> for
* fixing the problem with the BIOS on some Acer motherboards.
*
@@ -65,11 +22,6 @@
*
* Most importantly, thanks to Robert Bringman <[email protected]>
* 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>


2008-02-22 21:36:18

by Mark Lord

[permalink] [raw]
Subject: Re: [PATCH] ide: remove stale comments from ide-dma.c

Bartlomiej Zolnierkiewicz wrote:
> - 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.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
> ---
> drivers/ide/ide-dma.c | 48 ------------------------------------------------
> 1 file changed, 48 deletions(-)
>
> Index: b/drivers/ide/ide-dma.c
> ===================================================================
> --- a/drivers/ide/ide-dma.c
> +++ b/drivers/ide/ide-dma.c
> @@ -11,49 +11,6 @@
> */
>
> /*
> - * 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).
..

Those top comments still look relevant, or at least as relevant
as the rest of the file (and subsystem) itself. :)

Sigh.

Subject: Re: [PATCH] ide: remove stale comments from ide-dma.c

On Friday 22 February 2008, Mark Lord wrote:
> Bartlomiej Zolnierkiewicz wrote:
> > - 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.
> >
> > Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
> > ---
> > drivers/ide/ide-dma.c | 48 ------------------------------------------------
> > 1 file changed, 48 deletions(-)
> >
> > Index: b/drivers/ide/ide-dma.c
> > ===================================================================
> > --- a/drivers/ide/ide-dma.c
> > +++ b/drivers/ide/ide-dma.c
> > @@ -11,49 +11,6 @@
> > */
> >
> > /*
> > - * 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).
> ..
>
> Those top comments still look relevant, or at least as relevant
> as the rest of the file (and subsystem) itself. :)
>
> Sigh.

ide-dma.c supports _much_ more than IDE PCI BM-DMA nowadays :)

[ hmm, it probably makes sense to split CONFIG_BLK_DEV_IDEDMA_SFF code
to a separate file (ide-dma-sff.c?) so ide-dma.c would contain only
generic code ]

anyway here goes "take 2":

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

Cc: Mark Lord <[email protected]>
[...]

interdiff:

diff -u b/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
--- b/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -1,9 +1,13 @@
/*
+ * IDE DMA support (including IDE PCI BM-DMA).
+ *
* Copyright (C) 1995-1998 Mark Lord
* Copyright (C) 1999-2000 Andre Hedrick <[email protected]>
* 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).
*/

/*