Re: DMA on DVD/RW Inspiron 6000
- Dan Christensen <jdc@...> writes:
> garry191 <garry191@...> writes:I figured out how to get the higher speed. My DVD drive is a
>> Hi Guys, dd access to my DVD drive on Inspiron 6000 is very slow.
>> hdparm informs me that DMA is not supported on this device. Any tweaks
>> to make the DVD faster?
> I'm struggling with a similar issue on a Latitude D810 right now. The
> good news is that with Ubuntu's 2.6.12 kernel, the dvd drive is at
> /dev/scd0 and the access is just fast enough that I can watch a dvd
> (hdparm reports 2.2 MB/s). I believe this is without dma, which
> I can't enable.
> The bad news is that with a self-compiled 22.214.171.124 kernel (with a very
> different .config), I tried ide-cd, so the drive appeared as /dev/hdc,
> and I only got 1.56 MB/s, and my dvd player stuttered. With ide-scsi,
> the drive appeared as /dev/sr0, and I only got 1.2 MB/s. Any
> suggestions for how to mimick the Ubuntu kernel's performance?
SATA device, so the key is to get libata to handle it, rather
than the ide layer.
It turns out that Ubuntu's kernel contains a patch to 2.6.12 which
turns on libata's handling of ATAPI devices. In 126.96.36.199, this is
controlled by a module option. If you have libata compiled in, it is
on the boot command line. If libata is a module, you want
options libata atapi_enabled=1
in a file in /etc/modprobe.d. (In my case, I had to put such a
file in the initrd since the module is loaded before the filesystem
Not sure if this will help the original poster, but it may help
others with SATA DVD drives.