stuck in cam with bad optical media

[Andriy Gapon]

[I am probably just having an unlucky day.]

I tried to burn (with growisofs) a DVD+RW disk which seems to have developed some
problems.
First, the burning process got stuck at the same percentage and the drive started
to make unusual sounds.  Then, the following messages appeared in system log:
kernel: (cd0:ahcich5:0:0:0): READ(10). CDB: 28 0 0 0 0 0 0 0 1 0
kernel: (cd0:ahcich5:0:0:0): CAM status: SCSI Status Error
kernel: (cd0:ahcich5:0:0:0): SCSI status: Check Condition
kernel: (cd0:ahcich5:0:0:0): SCSI sense: MEDIUM ERROR asc:2,0 (No seek complete)
kernel: (cd0:ahcich5:0:0:0): READ(10). CDB: 28 0 0 0 0 0 0 0 1 0
kernel: (cd0:ahcich5:0:0:0): CAM status: SCSI Status Error
kernel: (cd0:ahcich5:0:0:0): SCSI status: Check Condition
kernel: (cd0:ahcich5:0:0:0): SCSI sense: MEDIUM ERROR asc:2,0 (No seek complete)
kernel: (cd0:ahcich5:0:0:0): READ(10). CDB: 28 0 0 0 0 0 0 0 1 0
kernel: (cd0:ahcich5:0:0:0): CAM status: SCSI Status Error
kernel: (cd0:ahcich5:0:0:0): SCSI status: Check Condition
kernel: (cd0:ahcich5:0:0:0): SCSI sense: MEDIUM ERROR asc:2,0 (No seek complete)
kernel: (cd0:ahcich5:0:0:0): READ(10). CDB: 28 0 0 0 0 0 0 0 1 0
kernel: (cd0:ahcich5:0:0:0): CAM status: SCSI Status Error
kernel: (cd0:ahcich5:0:0:0): SCSI status: Check Condition
kernel: (cd0:ahcich5:0:0:0): SCSI sense: Deferred error: MEDIUM ERROR asc:2,0 (No
seek complete)
kernel: ahcich5: Timeout on slot 7
kernel: ahcich5: is 00000000 cs 00000180 ss 00000000 rs 00000180 tfd 58 serr 00000000
kernel: (cd0:ahcich5:0:0:0): cddone: got error 0x5 back

After that growisofs either remained or became stuck in the following state:
42433 100119 growisofs        initial thread   mi_switch+0x1de sleepq_switch+0xdb
sleepq_wait+0x45 _sleep+0x295 cam_periph_ccbwait+0x40 cam_periph_runccb+0x68
passioctl+0x260 devfs_ioctl_f+0xf8 kern_ioctl+0x262 ioctl+0x168 syscallenter+0x3be
syscall+0x41 Xfast_syscall+0xe2

Any commands that tried to access the device (cdcontrol eject, camcontrol reset
5:0:0) also got stuck.
Only reboot helped to recover the device.

I understand that bad media is bad, but it happens.
I think that cam and ahci typically recover from errors/timeouts, so somehting
must have gone wrong in this case.

P.S. I have already thrown out the bad disk - irritation won over reason when that
happened, unfortunately :(
-- 
Andriy Gapon