can't turn DMA on my hard drive

slzckboy · 09-22-2005, 08:05 PM

Hello

I have double checked my kernel configs and I have the right drivers compiled in for my IDE chipset.

However I am unable to turn dma on,which is causing me as few performance issues etc.

when I do hdparm -d1 /dev/hdb i get

Code:

/dev/hdb:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

I also have tried parsing

ide-scsi ide0=dma ide1=dma to the kernel at boot time via grub because i thought i read somehwere that you can't activate dma to a mounted device ??

anyway it didn't work.

You help is much appreciated as ever.

addy86 · 09-23-2005, 02:36 AM

Have you tried doing it as root?

Quote:

Originally posted by slzckboy
...because i thought i read somehwere that you can't activate dma to a mounted device ??

Well, since complete hard drives are rarely mounted (but partitions), this should not apply. As far as I remember, I can active DMA on hard drives that contain mounted partitions.

slzckboy · 09-23-2005, 04:32 AM

yes
I have done it as root.

addy86 · 09-23-2005, 06:48 AM

Have you already looked in your BIOS settings (just a guess)?

Or maybe your hardware is so old that it doesn't support DMA

wpyh · 09-23-2005, 08:43 PM

I have this in my lilo.conf instead:

append="ide0=ata66 ide1=ata66 hdc=ide-scsi"

Btw, are you using the correct 80-wire cable?

slzckboy · 09-24-2005, 06:58 AM

Age of my hardware is not an issue.
I should have said that it worked ok with my 2.4.26 kernel

its only since i started using 2.6x kernels.

silly me.

I just booted my 2.4.26 and DMA is enabled for all my ide devices

back to the drawing board

slzckboy · 09-24-2005, 01:26 PM

# CONFIG_BLK_DEV_VIA82CXXX is not set

found above in my .config file
lspci

00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Mas

fingers x'd