DMA settings.....

[SwampDonkey]

Well the transition is coming along nicely and I'm actually enjoying myself ;D

I've got the sound sorted out so I thought I would have a play with the DVD drive. Threw in a movie and the video is choppy. I have a feeling I'm looking at DMA settings here.

hdparm -I for the drive gives the following;

/dev/dvd:

ATAPI CD-ROM, with removable media
Model Number: HITACHI DVD-ROM GD-8000
Serial Number:
Firmware Revision: 0005
Standards:
Likely used CD-ROM ATAPI-1
Configuration:
DRQ response: 50us.
Packet size: 12 bytes
Capabilities:
LBA, IORDY(can be disabled)
DMA: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 udma0 udma1 *udma2 udma3 udma4
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns

Problem is, I don't know where I'm starting from!! Is that saying that UDMA2 is currently being used? If so, is there anything else I should be looking for?

Thanks guys ......... Pete

[JimH]

Red Hat by default disables DMA on cdrom/dvd drivers. They do this to avoid problems with flakey hardware.

Enabling DMA has changed on 8.0 over previous releases. Add this to your /etc/modules.conf

options ide-cd dma=1

This setting will not take effect until you unload/reload the ide-cd module. Or reboot.

You can unload a module with:
/sbin/rmmod <module>

Note if the module is being used by something else you have to remove that module(s) first.

load a module

/sbin/insmod <module>

or

/sbin/modprobe <module>

Note: insmod and modprobe behave differently. Check out the manpages on them for more details.

You can view what modules are loaded with:

/sbin/lsmod

Jim H

[SwampDonkey]

Once again spot on Jim.

Welcome to my Xmas card list ;D ;D ;D

Thanks ..... Pete

[trommaster]

his address is...

:P :P :P