Hi Joe! On Sun, 10 Aug 2003, Joe Morris (NTM) wrote:
On 08/10/2003 10:31 AM, David wrote:
Got a new UDMA motherboard last year and started getting burn problems with CD-RW ide-scsi emulation that I never had before (with the same drive and same Linux on my old slow EIDE motherboard.) No consistent error messages, tried lots of different CD-R and CD-RW blanks
So I had to disable UDMA on the CD-RW to get it to burn using
Do you mean disabling it in the BIOS?
Nope - I mean disabling it in the kernel - which is what the hdparm does. My BIOS Setting give hardly any control (KS75A mobo)
hdparm -d1 X34 /dev/hdc
which I put in /etc/init.d/boot.local
Which ENABLES DMA. Actually, yours enables for udma 33. Just curious as it appears my CDRW has finally gone bad, and I was just wondering...
UDMA is a very fast form of DMA which seems to be buggy in my older CD-RW. Disclaimer - I don't understand all that follows - it was merely good enough for me. This is what hdparm says :-
sudo /sbin/hdparm -i /dev/hdc
/dev/hdc: Model=SONY CD-RW CRX140E, FwRev=1.0n, SerialNo= Config={ Fixed 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=on/off, tPIO={min:180,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4 DMA modes: sdma0 sdma1 sdma2 mdma0 mdma1 *mdma2 UDMA modes: udma0 udma1 udma2 AdvancedPM=no Notice that the star is agains the mdma2 - this is a result of the X34 command I put in in the boot script. WIthout this it comes up with the * agains one of the umda modes (umda2 as far as I recall) and fails early in burns - and makes coasters. Thats all David