[ltp] DMA?

Chris Bednar linux-thinkpad@www.bm-soft.com
Tue, 9 Jul 2002 15:54:46 -0500 (CDT)


On Tue, 9 Jul 2002, Jon Tabor wrote:

> Okay, I have one for the list.
> 
> I have my DVD drive on my TP600E (2645-4AU) working beautifully under 
> RedHat 7.3 with Ogle.  The only thing is, it's choppy.  So, I find that I 
> need to turn the DMA setting to on for the DVD drive.  No problem, a 
> little hdparm -d1 /dev/cdrom works fine.  
> 
> But, there's a problem -- when I reboot, the DMA gets turned off.  I've 
> taken to adding /sbin/hdparm -d1 /dev/cdrom to a small script that starts 
> Ogle, but I want a better solution.
> 
> Any ideas?

    A few:

  1) Put "ide0=dma ide1=dma" in for boot args. In LILO, this
    amounts to adding a line to /etc/lilo.conf:

     append="ide0=dma ide1=dma"

    You're probably using grub; the procedure should be similar.
    This will cause all ide disks on those busses to default to
    DMA.

  2) Add the hdparm trick to /etc/rc.local

    Not elegant, but it works.

  3) I think it can be done in /etc/sysctl.conf, but I don't know how.



----
Chris J. Bednar
Director, Distributed Computing
http://AdvancedDataSolutions.com/


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