Re: amd64 panics w/XEN_DOM0, not GENERIC

[Todd Kover <kovert%omniscient.com@localhost>]

 > > With the GENERIC (+DEBUG+DIAGNOSTIC) kernel, I got:
 > > 
 > > stdone error 5 count 32768 resid 0
 > 
 > So the device reported an EIO. You didn't get SCSI error messages before
 > the panic, did you ?
 > The attached patch may fix the panic, but I'm not sure it's correct.

The panic is now gone and has been the day you wrote the patch.  This
has been with both the GENERIC and XEN3_DOM0 kernels.

 > It could actually cause the driver to report an error, while the data
 > actually got written. But I'm not sure what the correct fix would be
 > in such a case ...

its almost certainly a partial write, though likely at least something
got written.  I'm not quite sure what the fix is, though in my case it
doesn't much matter as the file being written gets started fresh on
a new tape rather than picked up where it left off.  Obviously this
doesn't fix the general case...

 > I'm also interested to know if the aprint_error_dev("EOM detected") I
 > added fires up just before "fixing b_resid".

often it does, tho not always.  The EOMs do seem to approximate when an
actual tape fils up, thouth at least one of the 'stdone error 5's (Aug
28 01:28 00:00) likely corresponds to a tape not being loaded into the
tape drive.

I've attached some relevent sections from /var/log/messages.

thanks again for your help,
-Todd

---<snip>---

Aug 26 13:35:48 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 26 15:34:48 tarvalon /netbsd: st0: EOM detected
Aug 26 15:34:48 tarvalon /netbsd: st0: fixing b_resid
Aug 26 15:34:48 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 26 15:34:51 tarvalon /netbsd: st0: EOM detected
Aug 26 15:36:59 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 26 17:35:47 tarvalon /netbsd: st0: EOM detected
Aug 26 17:35:47 tarvalon /netbsd: st0: fixing b_resid
Aug 26 17:35:47 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 26 17:35:49 tarvalon /netbsd: st0: EOM detected
Aug 26 17:37:58 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 00:01:03 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 03:30:06 tarvalon /netbsd: st0: EOM detected
Aug 27 03:30:06 tarvalon /netbsd: st0: fixing b_resid
Aug 27 03:30:06 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 27 03:30:08 tarvalon /netbsd: st0: EOM detected
Aug 27 03:32:17 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 05:35:39 tarvalon /netbsd: st0: EOM detected
Aug 27 05:35:39 tarvalon /netbsd: st0: fixing b_resid
Aug 27 05:35:39 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 27 05:35:41 tarvalon /netbsd: st0: EOM detected
Aug 27 05:37:50 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 07:37:00 tarvalon /netbsd: st0: EOM detected
Aug 27 07:37:00 tarvalon /netbsd: st0: fixing b_resid
Aug 27 07:37:00 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 27 07:37:02 tarvalon /netbsd: st0: EOM detected
Aug 27 15:22:57 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 17:22:05 tarvalon /netbsd: st0: EOM detected
Aug 27 17:22:05 tarvalon /netbsd: st0: fixing b_resid
Aug 27 17:22:05 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 27 17:22:07 tarvalon /netbsd: st0: EOM detected
Aug 27 17:24:15 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 27 19:23:23 tarvalon /netbsd: st0: EOM detected
Aug 27 19:23:23 tarvalon /netbsd: st0: fixing b_resid
Aug 27 19:23:23 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 27 19:23:26 tarvalon /netbsd: st0: EOM detected
Aug 27 19:25:34 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 00:01:03 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 02:55:50 tarvalon /netbsd: st0: EOM detected
Aug 28 02:55:50 tarvalon /netbsd: st0: fixing b_resid
Aug 28 02:55:50 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 28 02:55:52 tarvalon /netbsd: st0: EOM detected
Aug 28 02:58:00 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 05:33:54 tarvalon /netbsd: st0: EOM detected
Aug 28 05:33:54 tarvalon /netbsd: st0: fixing b_resid
Aug 28 05:33:54 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 28 05:33:56 tarvalon /netbsd: st0: EOM detected
Aug 28 05:36:04 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 07:34:59 tarvalon /netbsd: st0: EOM detected
Aug 28 07:34:59 tarvalon /netbsd: st0: fixing b_resid
Aug 28 07:34:59 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 28 07:35:02 tarvalon /netbsd: st0: EOM detected
Aug 28 08:07:02 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 10:41:18 tarvalon /netbsd: st0: EOM detected
Aug 28 10:41:18 tarvalon /netbsd: st0: fixing b_resid
Aug 28 10:41:18 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 28 10:41:21 tarvalon /netbsd: st0: EOM detected
Aug 28 10:43:32 tarvalon /netbsd: st0: error 5 in st_load (op 1)
Aug 28 15:46:29 tarvalon /netbsd: st0: EOM detected
Aug 28 15:46:29 tarvalon /netbsd: st0: fixing b_resid
Aug 28 15:46:29 tarvalon /netbsd: stdone error 5 count 32768 resid 32768
Aug 28 15:46:31 tarvalon /netbsd: st0: EOM detected
Aug 28 15:48:43 tarvalon /netbsd: st0: error 5 in st_load (op 1)