I have installed a Suse 8.1 Professional and I have updated it to a 2.6.11.7 kernel.

when i use my cd-rw to burn a cd it works very slow. I saw that dma is not enabled for my cd-rw. When I try to set it up with

hdparm -d1 /dev/hdb

i get:

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

My ide chipset is a KT400 and cd-rw is using linux ide-cdrom driver

How can i set up dma?

Is DMA enabled in your kernel?????
you may need to re-compile a new one........with DMA support

Did you recompile the kernel yourself? If so, I found that if I enabled "Generic IDE Support", I was unable to enable DMA on my drives.

Sorry i'm newbie and i need the exact option. in my configuration kernel i have:

* generic/default IDE chipset support. it's on.

* generic PCI IDE chipset support. it's on.

What of this two options i have to turn off?

I have set 'No' to the following:
generic/default IDE chipset support (IDE_GENERIC)
Generic PCI IDE Chipset Support (BLK_DEV_GENERIC)

I have a Asus A7V8X-X motherboard and turning both of those off works properly for my on 2.6.11.5:

00:00.0 Host bridge: VIA Technologies, Inc. VT8377 [KT400/KT600 AGP] Host Bridge

I have the same motherboard as you.

Have your turned on any model of chipset?

I switched to off that two options and I recompiled my kernel. then i restarted my compute and I get a kernel panic VFS culdn't mount my hard disk.

Why?

DMA cotinue off.

Because you haven't compiled in any IDE controller support.

As someone earlier asked, did you enable DMA support in the kernel? There is an option for it.

In my 2.6 kernel I have:
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_GENERIC_ISA_DMA=y (not really relevant)
CONFIG_BLK_DEV_IDEDMA=y

as the only DMA options. I also have the same chipset as you.

(by the way, you'll find those 4 lines in the .config file in the kernel source directory)

I have the four options you said as you said.

What more can i see?

That's just the DMA options...have you enabled an IDE controller?
The complete IDE section of my .config file is:

this is my dma config, the only diference with your it's that i have blk_dev_via82cxxx as module. I configure it with y, compile and told you after.

# IDE chipset support/bugfixes
#
CONFIG_IDE_GENERIC=y
CONFIG_BLK_DEV_CMD640=y
# CONFIG_BLK_DEV_CMD640_ENHANCED is not set
# CONFIG_BLK_DEV_IDEPNP is not set
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
# CONFIG_BLK_DEV_OFFBOARD is not set
CONFIG_BLK_DEV_GENERIC=y
# CONFIG_BLK_DEV_OPTI621 is not set
CONFIG_BLK_DEV_RZ1000=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
# CONFIG_BLK_DEV_IDEDMA_FORCED is not set
CONFIG_IDEDMA_PCI_AUTO=y
# CONFIG_IDEDMA_ONLYDISK is not set
# CONFIG_BLK_DEV_AEC62XX is not set
# CONFIG_BLK_DEV_ALI15X3 is not set
# CONFIG_BLK_DEV_AMD74XX is not set
# CONFIG_BLK_DEV_ATIIXP is not set
# CONFIG_BLK_DEV_CMD64X is not set
# CONFIG_BLK_DEV_TRIFLEX is not set
# CONFIG_BLK_DEV_CY82C693 is not set
# CONFIG_BLK_DEV_CS5520 is not set
# CONFIG_BLK_DEV_CS5530 is not set
# CONFIG_BLK_DEV_HPT34X is not set
# CONFIG_BLK_DEV_HPT366 is not set
# CONFIG_BLK_DEV_SC1200 is not set
CONFIG_BLK_DEV_PIIX=y
# CONFIG_BLK_DEV_NS87415 is not set
# CONFIG_BLK_DEV_PDC202XX_OLD is not set
# CONFIG_BLK_DEV_PDC202XX_NEW is not set
# CONFIG_BLK_DEV_SVWKS is not set
# CONFIG_BLK_DEV_SIIMAGE is not set
# CONFIG_BLK_DEV_SIS5513 is not set
# CONFIG_BLK_DEV_SLC90E66 is not set
# CONFIG_BLK_DEV_TRM290 is not set
CONFIG_BLK_DEV_VIA82CXXX=m
# CONFIG_IDE_ARM is not set
# CONFIG_IDE_CHIPSETS is not set
CONFIG_BLK_DEV_IDEDMA=y
# CONFIG_IDEDMA_IVB is not set
CONFIG_IDEDMA_AUTO=y
# CONFIG_BLK_DEV_HD is not set

That was. I have compiled my kernel with blk_dev_via82cxxx=y, not blk_dev_via82cxxx=m as before.

And now hdparm -d1 /dev/hdb works perfectly. DMA is active.

Thanks.

Man, what a headache -

I seem to have the same problem, but your solution doesn't work for me. The IDE controller chipset is different - VIA VT82C586A, but you guys seem to be using the same driver, VIA82cxxx. I've done everything suggested in the previous posts in the thread - disabling the generic IDE support, enabling VIA, and setting all my kernel options to the same as your IDE/bug-fix section. Recompiled, rebooted, and still hdparm -d /dev/hda gives me:

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

worked for me thank you guys

gigabyte motherboard with sis chipset the referred module is sis5513

Thank you

I switched from 2.6.10 to 2.6.11 and everything worked fine - don't know why. The config files I used for compiling looked exactly the same. Not a very happy resolution to the problem, in that it wasn't much of a learning experience, but - oh, well - win some, loose some; choose your battles; etc.