Re: Cannot enable DMA od DVD burner under 2.6.12
On Fri, 05 Aug 2005, ?á?ek Kry?tof wrote:
> I have SATA disk on /dev/sda and IDE DVD burner (LG) on /dev/hda. The chipset is Intel 82801EB.
> I fought hard to install Debian on this machine with debian-installer's linux26 (atapi-piix SATA driver is crap in 2.6).
>
> Now DVD works and I would like to enable DMA on the IDE /dev/hda burner but hdparm gives:
>
> hdparm -d1 /dev/hda
>
> /dev/hda:
> setting using_dma to 1 (on)
> HDIO_SET_DMA failed: Operation not permitted
> using_dma = 0 (off)
>
> I am using the stock debian kernel 2.6.12-1-686 and up-to-date unstable system.
khazad-dum:~# lspci
0000:00:00.0 Host bridge: Intel Corp. 82875P Memory Controller Hub (rev 02)
[...]
0000:00:1f.1 IDE interface: Intel Corp. 82801EB/ER (ICH5/ICH5R) Ultra ATA 100 Storage Controller (rev 02)
0000:00:1f.2 IDE interface: Intel Corp. 82801EB (ICH5) Serial ATA 150 Storage Controller (rev 02)
(I.e. this is a ICH5R, on a 875P machine from Intel itself).
khazad-dum:~# hdparm -d -u /dev/hda /dev/hdc
/dev/hda:
unmaskirq = 1 (on)
using_dma = 1 (on)
/dev/hdc:
unmaskirq = 1 (on)
using_dma = 1 (on)
Both drives above are PATA ATAPI CD/DVD burners, connected through UDMA
80-conductors cabling, and operating at UDMA2 (33Mbit/s). CPU utilization
during 16x DVD access is < 1%.
khazad-dum:~# uname -a
Linux khazad-dum 2.6.12.3-debian1+atapassthru+bluesmoke #1 SMP Tue Aug 2 01:48:26 BRT 2005 i686 GNU/Linux
The atapassthrough patches are used to enable SMART functionality on the
SATA disks, and have nothing to do with the PATA ATAPI DMA.
So, it should just work. Make sure you don't have something stupid such as
that "enable DMA only for disks" option enabled in your kernel configuration.
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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