Hi

Recenlty (after a xine upgrade from Suse's update) my DVD player had gaps in audio and video playing. I soon found out the DMA had been turned off.
I tried to turn it on in Yast >> error message. I turned it on with hdparm and it worked. I then included hdparm in my boot sequence. However, everytime I eject a DVD the DMA will turn itself off again.
I also noticed I need to press the eject button/use the eject command twice before the DVD comes out. DMA craps out after the first attempt. How can this be left on permanently? I heard Windows will disable DMA after playing a few scratchy DVDs but I would never think this of Linux. Could it be xine?


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Suse 10.1 2.6.16.27-0.6-default
libxine 1.1.4-0.pm.0
hdparm -i
Model=_NEC DVD_RW ND-3550A, FwRev=1.05, SerialNo=
Config={ Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
BuffType=unknown, BuffSize=0kB, MaxMultSect=0
(maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
IORDY=yes, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 *udma2
AdvancedPM=no
-------------------------------------------

What does this mean?

Did you try "YaST2 --> Hardware --> DMA Mode" and it had an error? If so what was the error. That might be the cause of the problem. Try using the YaST2 configuration if it exists instead of inserting your own scripts. You might get into a dueling configurations problem.

Actually yast says somthing along the lines of " can not change device %1 to mode %2..." it will not let me do anything in the yast-dma module.

I learned to trawl /var/log/messages and get this stuff (hda is the DVD)
the DMA and ATAPI reset is quite frequent:

Feb 9 19:55:04 spxx kernel: ISO 9660 Extensions: Microsoft Joliet Level 3
Feb 9 19:55:04 spxx kernel: ISOFS: changing to secondary root
Feb 9 20:21:45 spxx syslog-ng[2553]: STATS: dropped 0
Feb 9 20:29:08 spxx kernel: hda: irq timeout: status=0xd0 { Busy }
Feb 9 20:29:08 spxx kernel: ide: failed opcode was: unknown
Feb 9 20:29:08 spxx kernel: hda: DMA disabled
Feb 9 20:29:08 spxx kernel: hda: ATAPI reset complete
Feb 9 20:29:52 spxx kernel: hda: command error: status=0x51 { DriveReady SeekComplete Error }
Feb 9 20:29:52 spxx kernel: hda: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
Feb 9 20:29:52 spxx kernel: ide: failed opcode was: unknown
Feb 9 20:29:52 spxx kernel: end_request: I/O error, dev hda, sector 1248
Feb 9 20:29:52 spxx kernel: UDF-fs INFO UDF 0.9.8.1 (2004/29/09) Mounting volume 'G3_28201', timestamp 2005/11/17 13:06 (103c)
Feb 9 21:21:45 spxx syslog-ng[2553]: STATS: dropped 0

So it's the kernel killing DMA! But why is yast stuck?

There are different DMA modes. Either the drive doesn't support any, or you tried the wrong one. Try DMA/33. That may be the highest rate for a CD/DVD drive.

Hmmm....Problem is, the DMA switch in Yast is frozen (e.g. error message after I hit 'apply' ) - whatever option I choose, even turning it off!!!!
It used to run perfectly for 6 month. Now the kernel keeps dropping it - see above.

My DVD is capable of UDMA66
It is a 18x18x10 burner so perhaps the high speed requires it
It has a high CPU requirement as well, P4 2.4 GHz