Debian : no DMA with 2.4.21

From: Jay (Jay_at_free.fr)
Date: 07/16/03 

Date: Wed, 16 Jul 2003 21:54:14 +0200

Hello,

I'm using Debian Woody. I had a 2.4.18 kernel before
(kernel-image-2.4.18-686) and I decided to compile my own.
So I downloaded a 2.4.21 from kernel.org and compiled it the classic
way (make menuconfig, make dep clean bzImage modules modules_install, cp
arch/i386/boot/bzImage /boot/vmlinuz etc etc) not the Debian way.
Everything works great but I no longer have DMA!

Here's what I got :

toshiba:/home/jrn# hdparm -d /dev/hda
/dev/hda:
 using_dma = 0 (off)

toshiba:/home/jrn# hdparm -d1 /dev/hda
/dev/hda:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma = 0 (off)

What the hell is that? Here's my .config portion concerning DMA:

toshiba:/home/jrn# cat /usr/src/linux-2.4.21/.config|grep DMA
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_IDEDMA=y
# CONFIG_IDEDMA_PCI_WIP is not set
# CONFIG_BLK_DEV_ADMA100 is not set
# CONFIG_HPT34X_AUTODMA is not set
CONFIG_IDEDMA_AUTO=y
# CONFIG_IDEDMA_IVB is not set
# CONFIG_DMA_NONPCI is not set
# CONFIG_SCSI_EATA_DMA is not set

I'm pretty sure DMA is not enabled because hdparm -Tt /dev/hda gives me
this :

toshiba:/home/jrn# hdparm -Tt /dev/hda
/dev/hda:
 Timing buffer-cache reads: 128 MB in 0.37 seconds =345.95 MB/sec
 Timing buffered disk reads: 64 MB in 21.09 seconds = 3.03 MB/sec

(Timing buffered disk reads used to be 29 MB/sec with my old kernel and
DMA enabled).

Thanks for your help, I really need DMA! 

-- 
Toshiba laptop - P IV 1.7 GHz - Debian GNU/Linux (Woody 3.0r1)

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