Re: DMA not permitted since 2.6.14
Hi David,
First of all, I do not have the exact same controller that you have
(mine is an Intel Corporation 82801DBM (ICH4-M) IDE Controller).
However, since I had the same problems when I tried to use PIIX
as a module, I hope what I write below might be helpful to you.
My 2.6.14 kernel was compiled from the Debian package
linux-source-2.6.14-2 without any additional patches, using make-kpkg
with yaird for the initrd-generation. PIIX is included in the kernel and
I do not have any entry for it in my output of lsmod. (This seems to be
one important difference between your configuration and mine.) DMA gets
turned on automatically during boot, and I get transfer rates of about
25-30 MB/s.
The fact that menuconfig does not let you select the PIIX driver as a
static part of the kernel (<*> instead of <m>) makes me suspect that you
have accidentally disabled some other necessary option. (In such a case
it does indeed not help to change the .config-file manually since the
inconsistency will be detected when you try to compile the kernel.)
I have pasted the relevant part of my .config file below, maybe a
comparison with your .config will tell you which option you should try
to activate. (There are a few more which are related to DMA, they are
all in "Device Drivers ---> ATA/ATAPI/MFM/RLL support" if you use
menuconfig.)
I hope this helps.
Regards,
Florian
==================== part of my .config ====================
#
# ATA/ATAPI/MFM/RLL support
#
CONFIG_IDE=y
CONFIG_BLK_DEV_IDE=y
#
# Please see Documentation/ide.txt for help/info on IDE drives
#
# CONFIG_BLK_DEV_IDE_SATA is not set
# CONFIG_BLK_DEV_HD_IDE is not set
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_IDEDISK_MULTI_MODE=y
CONFIG_BLK_DEV_IDECS=m
CONFIG_BLK_DEV_IDECD=y
CONFIG_BLK_DEV_IDETAPE=m
CONFIG_BLK_DEV_IDEFLOPPY=m
CONFIG_BLK_DEV_IDESCSI=m
# CONFIG_IDE_TASK_IOCTL is not set
#
# 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 is not set
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_IT821X is not set
# 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 is not set
# CONFIG_IDE_ARM 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
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