can not enable dma on laptop cd/dvd

megaspaz · 09-01-2003, 02:25 PM

my dad came over and i installed red hat 7.3 on his dell latitude c800 laptop. his laptop is about 6-7 months newer than mine. the problem i'm having is that enabling dma on his fixed dvdrom drive and the modular bay cdrw is failing. my laptop, dell inspiron 8100, has a fixed cdrw drive and modular bay dvdrom drive and dma enables fine for both of them. anyway, i was thinking that is because his modular bay cdrw is an atapi device, but his fixed dvdrom won't enable dma either and both of my devices enable dma fine. the only thing different on the install and setup that's different from mine is that he installed the red hat ntfs support patch rpm. any ideas? below is some hdparm info on my dad's modular bay cdrw.

Code:

[root@donslap ~]# hdparm -I /dev/hdc

/dev/hdc:

ATAPI CD-ROM, with removable media
        Model Number:           TOSHIBA CD-RW/DVD-ROM SD-R2002
        Serial Number:
        Firmware Revision:      1E29
Standards:
        Used: ATAPI for CD-ROMs, SFF-8020i, r2.5
        Supported: CD-ROM ATAPI-2
Configuration:
        DRQ response: 50us.
        Packet size: 12 bytes
Capabilities:
        LBA, IORDY(can be disabled)
        Buffer size: 2048.0kB
        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=120ns

	     

[root@donslap ~]# hdparm -d1 /dev/hdc

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

any suggestions on fixes are much appreciated. thanks.

finegan · 09-06-2003, 06:38 AM

hdparm only works on actual hard drives, regardless, its info reading says that the drive is set for ultra dma, the star next to udma2 means its set for, more or less, ATA33.

Cheers,

Finegan

megaspaz · 09-08-2003, 09:01 PM

thanks for replying finnegan, but it still seems so wierd to me, because dma is enabled, as i said before for my cdrw and dvd.

Quote:

[root@Tron root] $ hdparm -I /dev/hdc
/dev/hdc:

ATAPI CD-ROM, with removable media
Model Number: TOSHIBA DVD-ROM SD-C2502
Serial Number: 3200009153
Firmware Revision: 1D13
Standards:
Used: ATAPI for CD-ROMs, SFF-8020i, r2.5
Supported: CD-ROM ATAPI-2
Configuration:
DRQ response: 50us.
Packet size: 12 bytes
Capabilities:
LBA, IORDY(can be disabled)
Buffer size: 128.0kB
DMA: sdma0 sdma1 sdma2 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=120ns

[root@Tron root] $ hdparm -v /dev/hdc
/dev/hdc:
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 1 (on)
readahead = 8 (on)
busstate = 1 (on)

it looks like my peripheral says the same thing as my dad's, but as you can see with the hdparm -v, dma is enabled, where as it won't enable on my dad's modular cdrw (doing an hdparm -v will show using_dma = 0 (off) ). this pretty much makes burning cds and watching dvds impossible due to the extreme sluggishness of accessing the data... we tried burning a cd, but just the cdrw scan was taking forever. what could be the difference, considering at least for his modular bay cdrw and my modular bay dvd player are both made by toshiba, his cpu and my cpu are both 1Ghz, and we're both running 512MB of sdram?