PCI IDE DMA how to configure?

PCI IDE DMA how to configure?

Post by Urban Koistin » Thu, 18 Sep 1997 04:00:00



I want to read large blocks from disk to ram, and do calculations
in parallel and I have noticed that reading uses much cpu.
To free up the cpu I try to enable dma with the command:
hdparm -d 1 /dev/hdb
but I get:
HDIO_SET_DMA failed: Operation not permitted

What might be wrong?
According to the manual my motherboard should support dma.
What do I have to do to get DMA working?
Should I try disconnecting most devices except /dev/hdb?

Now I run Linux debian 2.1.54 #10 i586

My system has:
SiS 85C501/502/503 Chipset
PCI QD8580 IDE on board
NCR53c810 (according to kernel. I think that is correct)
SCSI CDR&Scanner
/dev/hda is SAMSUNG SHD-3212A (APOLLO-4) AD
/dev/hdb is QUANTUM FIREBALL1080A
/dev/hdc is FX001DE
P90

hda&hdb has DMA according to hdparm -i but hdc is lacking it.
hdc is a 4X CD-rom reader.

There is no occurance of 8580 in /var/log/messages

Urban Koistinen

 
 
 

PCI IDE DMA how to configure?

Post by Urban Koistin » Sun, 21 Sep 1997 04:00:00




! >I want to read large blocks from disk to ram, and do calculations
! >in parallel and I have noticed that reading uses much cpu.
! >To free up the cpu I try to enable dma with the command:
! >hdparm -d 1 /dev/hdb
! >but I get:
! >HDIO_SET_DMA failed: Operation not permitted

! [...]

! I do get the same message since I've updated to a TX chipset
! motherboard. From what I'ver read, you'll need a patch for
! the driver to enable hdparm operations on this chipset.

Where can I find the patch?

In 2.1.54 QD8580 is listed in ide.h

Urban Koistinen