Subject: Re: Bus-Master DMA error: missing interrupt
To: None <>
From: Manuel Bouyer <>
List: current-users
Date: 12/25/1998 20:44:58
On Dec 23, Zdenek Salvet wrote
> Yes, PIO 4 works, but it sucks too much CPU time
> (32Max CDROM -> 45% of Pentium II/400Mhz). I am going to try other drives
> next week, maybe my drive or cable is defective.

Or it's just the combination of your hard disk and CD which doesn't work ...
I've seen an IBM not behave properly when there is a ZIP drive on the
same cable ...

> Something is not initialized on startup but is reinitialized after error.

The reset makes it off. I don't know why it stays on, maybe a transfert
doesn't go to end ... I don't know to which signal the busy led is connected.

> BTW, cd driver does not properly check request size when reading
>      through the end of partition, dd if=/dev/rcd0a of=/dev/null bs=64k
>      results in 
> cd0(pciide0:1:1):  Check Condition on CDB: 0x28 00 00 04 d6 00 00 00 20 00
>     SENSE KEY:  Illegal Request
>      ASC/ASCQ:  Logical Block Address Out of Range

For now, I don't think anything initialize the partition table;
the 'a' partition acts as a raw partition.

Manuel Bouyer, LIP6, Universite Paris VI.