Dma support with CF-Card

Question

Hi there:
I have a problem here. I can't enable DMA with my 2gb CF Card (Sandisk Ultra 2.0). Its connected to the IDE Port and Archlinux with Kernel 2.6.28-ARCH.
hdparm -d1 /dev/sda1 just returns
/dev/sda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Inappropriate ioctl for device
HDIO_GET_DMA failed: Inappropriate ioctl for device
I know that DMA is supported by this device, here is the output from hdparm -vI /dev/sda:
/dev/sda:
IO_support = 0 (default)
readonly = 0 (off)
readahead = 256 (on)
geometry = 249/255/63, sectors = 4001760, start = 0
CompactFlash ATA device
Model Number: SanDisk SDCFH-2048
Serial Number: 014212E2907A1203
Firmware Revision: HDX 4.04
Standards:
Supported: 4
Likely used: 4
Configuration:
Logical max current
cylinders 3970 3970
heads 16 16
sectors/track 63 63
CHS current addressable sectors: 4001760
LBA user addressable sectors: 4001760
device size with M = 1024*1024: 1953 MBytes
device size with M = 1000*1000: 2048 MBytes (2 GB)
cache/buffer size = 1 KBytes (type=DualPort)
Capabilities:
LBA, IORDY(may be)(cannot be disabled)
Standby timer values: spec'd by Vendor
R/W multiple sector transfer: Max = 4 Current = 0
DMA: mdma0 mdma1 mdma2 (?)
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
Commands/features:
Enabled Supported:
* CFA feature set
Its running on a Via Motherboard, i think i loaded the right chipset modules. IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686, Module is /lib/modules/2.6.28-ARCH/kernel/drivers/ide/via82cxxx.ko, but this did not change anything. I also tried to include some kernelline commands, but they also didnt help.
There are some other "errors" appearing on boot:
Mar 8 03:06:03 media sd 1:0:0:0: [sda] 4001760 512-byte hardware sectors: (2.04 GB/1.90 GiB)
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write Protect is off
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Mar 8 03:06:03 media sd 1:0:0:0: [sda] 4001760 512-byte hardware sectors: (2.04 GB/1.90 GiB)
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write Protect is off
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Mar 8 03:06:03 media sda:<3>ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
Mar 8 03:06:03 media sda1
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Attached SCSI removable disk
Mar 8 03:06:03 media sd 1:0:0:0: [sda] 4001760 512-byte hardware sectors: (2.04 GB/1.90 GiB)
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write Protect is off
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Mar 8 03:06:03 media sda: detected capacity change from 0 to 2048901120
Mar 8 03:06:03 media sd 1:0:0:0: [sda] 4001760 512-byte hardware sectors: (2.04 GB/1.90 GiB)
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write Protect is off
Mar 8 03:06:03 media sd 1:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Mar 8 03:06:03 media sda: detected capacity change from 0 to 2048901120
Do you have any ideas how i can enable DMA with this card and remove this messages from booting?
Thank you all very much
andieh

Answer 1

I have three CF cards installed in my computer, each is an adata 266x UDMA capable 8GB.
I utilize IDE to CF card adapters for utilizing CF cards in my system or SATAII to CF cards adapters.
I obtain 45MB/sec sequential speed on all three adapters.
These are UDMA capable CF cards, not just DMA.
Currently, I utilize all three CF cards in a raid0 arrangement using a dual pci-e to SATAII adapter to two CF adapters and a single pci-e adapter to SATAII and a CF adapter as well.  The three perform at 45MB/S and 130 MB/S in the raid array.
Each card is identified as an sd(x) card.
Kernel is the latest to date.
DMA utilization may limit your speed to less than 20MB/s and IDE operation with an adapter from pci performs well with UDMA.
I realize I haven't addressed your particular problem directly but I find that in the latest kernels a pci to IDE adapter permits full performance from CF cards whereas using the mobo IDE slot does not...probably due to libata inclusion in the kernel.  YMMV