Getting DMA under Linux to work on this board is a bit of an excersize. What was finally needed was to download a 2.6.12 kernel (FC3 comes with 2.6.9-something, which don't seem to do DMA with this board).

Then, the whole kernel install procedure was followed (see http://www.mjmwired.net/resources/mjm-kernel-fc3.shtml). The trick is, after doing xconfig and configuring the kernel, you must edit .config in the kernel source directory (this file is created by xconfig) and make sure the line

CONFIG_BLK_DEV_ATIIXP=y

is present AND set to "=y", as well as all lines that refer to DMA are set to "y":

CONFIG_GENERIC_ISA_DMA=y
CONFIG_ISA_DMA_API=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_BLK_DEV_IDEDMA_FORCED=y
CONFIG_IDEDMA_PCI_AUTO=y
# CONFIG_IDEDMA_ONLYDISK is not set
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_IVB=y
CONFIG_IDEDMA_AUTO=y

(you can leave the CONFIG_IDEDME_ONLYDISK unset)

Now, compile your kernel using the steps indicated at http://www.mjmwired.net/resources/mjm-kernel-fc3.shtml.

Make sure you edit your /etc/inittab (BEFORE rebooting into the new kernel) to use runlevel 3. This is needed in case you had a NVidia driver installed, which won't now start with the new kernel.

Change the line that reads

id:5:initdefault:

(in a standard FC3 install)

to

id:3:initdefault:

in /etc/inittab to make the new kernel start in textmode.

Reboot into the new kernel.

Once you are in, login as root and try

/sbin/hdparm -d1 -c1 /dev/hdc

to see if you can set DMA mode on the DVD/CDROM drive. If it works, (no HDIO_SET_DMA error messages) you are sitting pretty. Now try

/sbin/hdparm -d1 -c1 /dev/hda

to see if you can enable DMA on the IDE harddrive (if you have one). This should also work without any HDIO_SET_DMA error messages.

Congratulations! You have now enabled kernel DMA with FC3 Linux on the Gigabyte GA-8TRS350MT motherboard based on the ATi RS350 chipset with ATI SB300(IXP 300) south bridge / southbridge.

Now, reinstall your NVidia drivier if any. Always make sure you have the latest NVidia Linux driver from NVidia.com.

There you have it! You should now be able to edit /etc/inittab again as detailed above and make the "3" a "5" - to start in Xwindows on bootup, and stuff like Xine and Mplayer should now be able to use DMA on the GA-8TRS350MT to play DVD's with no hiccups or choppiness.

Feel free to mail me at spamnot@<removethis>polard.com if you have problems regarding the above, or if you want the kernel .config I have that enables me to do DMA with FC3 on this motherboard.

Stefan Viljoen