i have a dell lattitude d610 laptop. it has a SATA hard drive and an IDE dvd/cdrw combo drive.
i cant get DMA enabled on the dvd/cdrw combo drive. i first noticed this problem when tyring to play a DVD, and xine helpfully told me that i was losing lots of frames and suggested that i run xine-check.
a xine-check snip...
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[ hint ] DMA is disabled for your DVD interface.
This will probably result in a serious performance hit when
playing DVDs. You can issue the command
hdparm -d1 /dev/hdc
as root to enable DMA. It would be wise to add this command to
some script that is executed executed at boot time.
Note that you probably have to set the DMA mode for your drive as well.
Most DVD-ROMs work fine with multiword DMA mode 2. You can use
hdparm -d1 -X34 /dev/hdc
(as root again) to set this mode. Maybe UDMA2 will give you even better
performance, but it only works well with some controllers. You'll
probably need UDMA capable IDE cables for this mode. If you want
to try: make backups of your important data and type (as root again)
sync
hdparm -d1 -X66 /dev/hdc
If your System still works fine after this, you probably want to keep
these settings (add them to some boot script).
If your system hangs or behaves very strangely after a few minutes, you
should reboot immediately and never use this setting again on this
machine. Good luck ;-)
press <enter> to continue...
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ramiken root # hdparm -Tt /dev/hdc
/dev/hdc:
Timing cached reads: 2108 MB in 2.00 seconds = 1053.63 MB/sec
Timing buffered disk reads: read(2097152) returned 163840 bytes
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ramiken root # hdparm -d 1 /dev/hdc
/dev/hdc:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)Code: Select all
ramiken root # hdparm -I /dev/hdc
/dev/hdc:
ATAPI CD-ROM, with removable media
Model Number: _NEC DVD+/-RW ND-6500A
Serial Number:
Firmware Revision: 202C
Standards:
Likely used CD-ROM ATAPI-1
Configuration:
DRQ response: 3ms.
Packet size: 12 bytes
Capabilities:
LBA, IORDY(cannot be disabled)
DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120nhere is a relavent snip from lspci...
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0000:00:1f.2 IDE interface: Intel Corporation 82801FBM (ICH6M) SATA Controller (rev 03) (prog-if 80 [Master])
Subsystem: Dell: Unknown device 0182
Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 5
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at bfa0 [size=16]
Capabilities: [70] Power Management version 2Code: Select all
#
# 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_IDEDISK=y
CONFIG_IDEDISK_MULTI_MODE=y
CONFIG_BLK_DEV_IDECD=y
#
# IDE chipset support/bugfixes
#
CONFIG_IDE_GENERIC=y
CONFIG_BLK_DEV_CMD640=y
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
CONFIG_BLK_DEV_GENERIC=y
CONFIG_BLK_DEV_RZ1000=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_BLK_DEV_PIIX=y
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_AUTO=yi think there may be another useful output snip somewhere in /sys or /proc, but i cant find it.
)