Re: Help needed to solve SCSI problem

["William J. Earl" <wje@fir.engr.sgi.com>]

Thomas Bogendoerfer writes:
 > I'm now total stuck with the remaining SCSI problem, and need some help.
 > 
 > I have a really broken cdrom drive. With this cdrom I'm able produce a
 > scsi timeout, which will cause a hang of the complete machine. I've
 > traced the problem a little bit further, and detected, that I get
 > interrupts on interrupt vector 0 (it's named VECTOR_GIO0 in the Irix
 > header files). I always see 17 irq 0 then the machine hangs completly.
 > 
 > Please, could someone tell what this interrupt means, so I can either
 > solve it by servicing the interrupt the right way or avoid it by doing 
 > something else ?

      I believe that is the two bits:

#define EXTIO_HPC3_BUSERR		0x0010
#define EXTIO_SG_STAT_0			0x0001

HPC3_BUSERR means that the HPC3 got a bus error reading from memory.
The driver is probably broken and giving bad commands to the HPC3.
You should be able to find the error address in the GIO_ERR_ADDR register:

#define	GIO_ERR_ADDR	0x1fa000f4	/* GIO error address (w, ro) */

(0xbfa000f4 as a K1SEG address).