[vox-tech] DVD issues

[Peter Jay Salzman]

On Wed 11 Aug 04, 11:49 AM, Dylan Beaudette <dylan at iici.no-ip.org> said:
> > On Wed 11 Aug 04, 11:00 AM, dylan <dylan at iici.no-ip.org> said:
> >> Hi everyone,
> >>
> >> I was recently messing about with DVD playback on linux, and was less
> >> than
> >> impressed with the quality- i.e. playback was at about 75% speed. after
> >> some
> >> googling i came to the conclusion that I had 2 options: 1 get a better
> >> video
> >> card  or 2, fix the DMA settings on the drive with hdparm... (the xv
> >> extension to X11 was already installed)
> >>
> >>
> >> the initial output from hdparm was as follows:
> >> linux:/var/log # hdparm /dev/dvd
> >> ---------------------
> >> /dev/dvd:
> >>  HDIO_GET_MULTCOUNT failed: Invalid argument
> >>  IO_support   =  0 (default 16-bit)
> >>  unmaskirq    =  0 (off)
> >>  using_dma    =  0 (off)
> >>  keepsettings =  0 (off)
> >>  readonly     =  1 (on)
> >>  readahead    = 256 (on)
> >>  HDIO_GETGEO failed: Invalid argument
> >> ---------------------
> >>
> >> i tried a couple of combinations of turning on DMA, as well as toggling
> >> the
> >> other settings. Any setting other than the default lead to a
> >> non-functioning
> >> DVD drive, and the following lines in /var/log/messages:
> >> ---------------------
> >> Aug 10 22:40:00 linux kernel: hdd: drive_cmd: status=0x51 { DriveReady
> >> SeekComplete Error }
> >> Aug 10 22:40:00 linux kernel: hdd: drive_cmd: error=0x04Aborted Command
> >> ---------------------
> >>
> >> I have ordered a new video card for this machine, as the integrated
> >> video is
> >> awful. perhaps this will solve my problems. however, is it normal for a
> >> modern DVD drive like this one refuse to accept DMA transfers?
> >>
> >>
> >> any ideas?
> >>
> >> thanks in advance!
> >>
> >> Dylan
> >
> > Dylan, are you getting DMA on *any* of your hard drives?  In kernels
> > 2.6, you need to look at these settings:
> >
> >    Device Drivers | ATA/ATAPI/MFM/RLL support
> >
> > Do you see where it says things like "X support"?  You need to find the
> > correct IDE chipset for your motherboard and enable it.
> >
> > If you're using a distro supplied kernel, I'm surprised it's not being
> > loaded.  Look in dmesg and try to find error messages related to the IDE
> > system or with words like PIO and UDMA.  Try to load the relevent module
> > by hand and see if there are any error messages.
> >
> > I would be suprised if you had DMA on any of your drives if it's not
> > working on your DVD drive.
> >
> > I'm assumming your DVD drive is IDE/ATAPI.
> >
> > Pete
> >
> 
> Thanks to everyone who has responded thus far. A little more info on the
> system: it is a PIII @ 700mhz with 256mb RAM, running SUSE 9.1 personal.
> last i checked DMA was enabled on the HDD, but not on either the CDR / DVD
> drives... I don't have access to the machine right now, so i can't check
> dmesg, but I havn't noticed anything strange in there *yet*...
> 
> Also -- it is an IDE/ATAPI device, and ultraDMA is enabled in the bios.
> The kernel is the stock 2.6.x kernel bundled with SUSE 9.1... perhaps the
> machine just has a flaky IDE controller...?
> 
> dylan

Interesting.  I'm a little confused now.  I was under the impression
that DMA transfers had nothing to do with the drive itself, but what
you're saying is contradicting this.  I honestly don't know for sure
myself.  It's always been my understanding.

I'd do this in order:

1. Verify DMA is turned on for your hard drive.
2. Verify DMA can't be turned on for your DVD drive.
3. Look in dmesg for any fishy messages.
4. Google for your DVD drive make/model, "DMA" and "linux".
5. Report back what you find.  I'm curious how this resolves.

Pete

-- 
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