diff options
Diffstat (limited to 'drivers/ide/ide-dma.c')
| -rw-r--r-- | drivers/ide/ide-dma.c | 54 |
1 files changed, 5 insertions, 49 deletions
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c index d0e7b53..d61e578 100644 --- a/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 <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> @@ -757,7 +713,7 @@ static int ide_tune_dma(ide_drive_t *drive) } if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE) - return 0; + return 1; if (ide_set_dma_mode(drive, speed)) return 0; |