[CentOS] help with hdparm

I am running centos 5.2 i686.

The /boot/config indicates that VIA82CXXXX is built into the kernel.
CONFIG_BLK_DEV_VIA82CXXX=y

my lspci -v gives
00:0f.0 IDE interface: VIA Technologies, Inc. CX700M2 IDE (prog-if 8a 
[Master SecP PriP])
       Subsystem: VIA Technologies, Inc. Unknown device 0581
       Flags: bus master, medium devsel, latency 32
       I/O ports at fc00 [size=16]
       Capabilities: [b0] Power Management version 2

Which I think is the VIA part.

when I do "hdparm /dev/hdc" I get
/dev/hdc:
multcount    =  0 (off)
IO_support   =  0 (default 16-bit)
unmaskirq    =  0 (off)
using_dma    =  0 (off)
keepsettings =  0 (off)
readonly     =  0 (off)
readahead    = 256 (on)
geometry     = 15733/16/63, sectors = 15858864, start = 0

when I do "hdparm -d1 /dev/dhc" I get

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


I get operation not permitted.
How do I enable DMA mode for this device?

Jerry