Karl-Heinz Herrmann wrote:
On Mon, 06 Dec 2004 10:11:29 -0500 Bill Davidsen <davidsen@tmr.com> wrote:I have an interesting problem burning one CD, I keep gettingunderruns.You only mentioned *AUDIO* CD in the subject. audio CD's do not have sectors of 2048 bytes but somewhat longer. It seems ide-scsi can't handle this nonstandard sector size while using DMA. So while burningdata CD's you've got the DMA support and with audio you won't have it.The way around I know is to get a recent cdrecord which supportsATA/ATAPI interface and run the burner as IDE (not ide-scsi). "cdrecord -dev=ATA: -scanbus" should bring up the available devicenumbers. cdrecord documentation (man page *and* README's coming along with cdrecord source) should cover this topic.
I've had mixed results using non-ide-scsi with 2.4 kernels. There has been a lot of discussion on the kernel list on this (and I'm guilty of starting part of it), and I've had no problems using ATAPI: with a 2.6 kernel up to 48x but I'd rather not on 2.4.
My puzzlement is not how to get around the issue, but why it happens. I do appreciate the suggestion, Typically when doing a PIO burn the idle gets very low, but you don't get underruns until you run out of CPU. I get down to 10% idle on a 1GHz Athlon with a 40x burner and an old and very patched kernel. But system time is only ~30%, idle the rest.
BTW: the -scanbus option doesn't seem to work w/o ide-scsi using 2.4 and FC1. May well be a config option, I never use the ATA or ATAPI w/o a 2.6 kernel.
-- bill davidsen <davidsen@tmr.com> CTO TMR Associates, Inc Doing interesting things with small computers since 1979