Hard disk DMA

varunk · 06-06-2002, 05:35 AM

Hi,
I was trying to set the hdd DMA flag on but was facing the following problems :
hdparm -d1 /dev/hda :
/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)

The details of my computer are :
dmesg :
ide: Assuming 33MHz PCI bus speed for PIO modes; override with idebus=xx
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide0: probed IRQ 14 failed, using default.
ide1 at 0x170-0x177,0x376 on irq 15
ide1: probed IRQ 15 failed, using default.

why did it not show DMA etc? y is it still using PIO mode rather than ultra DMA.
I have VIA KT266 chipset with Seagate 40gb 5400 rpm hdd.I doubt if they do not support UDMA modes.
On the other hand :
hdparm -I /dev/hda :

Model=TS438001 A , FwRev=.306 , SerialNo=F61B9S20
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=unknown, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=78165360
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=yes: unknown setting
Drive Supports : Reserved : ATA-1 ATA-2 ATA-3 ATA-4 ATA-5 ATA-6

this shows that the drive supports UDMA modes.
I also checked the cable...it is conductor 80(UDMA) cable.what should i do now?
thanks for any help
Varun

taz.devil · 06-06-2002, 12:13 PM

As for the error suggests, you don't have permission to do that, only root does, try it that way. As far as PIO mode, are you sure it supports DMA?

ngomong · 06-06-2002, 10:36 PM

I'm having the same problem.

I tried hdparm -d1 /dev/hdb as root and got the same error.

My mobo supports ATA133, as does my harddrive.

I edited my /etc/sysconfig/harddisks file to enable DMA, but that didn't help.

In the output of dmesg, I have:

Code:

ide: Assuming 33MHz PCI bus speed for PIO modes; override with idebus=xx

Which file would I edit to do the override... and what do I replace "xx" with?

varunk · 06-07-2002, 01:47 AM

hi ,
If u have a mobo with VIA chipset then get the appropriate
patch for linux from the VIA site.It has all the instructions and the
patch works(worked for me).
best of luck
Varun

ngomong · 06-07-2002, 08:34 AM

Thanks! That pointed me in the right direction.

Unfortunately, I'm using a more current kernel than their patch supports. Their documents say that my chipset is supported natively as of kernel 2.5.2.

I tried messing with 2.5.20, but that led to other problems, and I got sidetracked.

Perhaps I'll try getting the patch to work... I'm anxious to see the speed improvements!

ngomong · 06-07-2002, 05:27 PM

Re-installed the default 2.4.7-10 kernel from RedHat, applied the patch, and it worked perfectly.

Now my harddrive quick, quick, quick.

varunk · 06-07-2002, 05:52 PM

hey,
Some of my services did not work...
u did something more after make bzImage?(make modules etc).

ngomong · 06-07-2002, 07:10 PM

Actually, since I had my old 2.4.7-10 kernel still installed, I just used those modules.

My grub.conf entries look like this:

Code:

title Red Hat Linux (2.4.7-10) w/ UDMA
	root (hd0,0)
	kernel /vmlinuz-2.4.7-10.UDMA ro root=/dev/hda3
	initrd /initrd-2.4.7-10.img
title Red Hat Linux (2.4.7-10)
	root (hd0,0)
	kernel /vmlinuz-2.4.7-10 ro root=/dev/hda3
	initrd /initrd-2.4.7-10.img

I also used the same old initrd image, which refers to my old modules.