> The attached patch should fix this, can you try it ?

i tried "dd if=/dev/rsd0c of=/dev/null" with your patch
and got EIO after the following messages on console.
is this an expected behaviour?

YAMAMOTO Takashi


esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40237464: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40237680: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x4023789c: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40237ab8: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40237cd4: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: disk label read error
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40237ef0: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40236168: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x40236384: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x402365a0: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing
sd0: sync (50.00ns offset 15), 16-bit (40.000MB/s) transfers, tagged queueing
esiop0: DMA IRQ: Illegal instruction DMA fifo empty, DSP=0x560 DSA=0x402367bc: T/L/Q=1/0/0 last msg_in=0x4 status=0xff
esiop0: scsi bus reset
sd0(esiop0:0:1:0): command with tag id 0 reset
sd0: async, 8-bit transfers, tagged queueing