caller is scsi_done which the controller interrupt handlers call. In the
case of a non-buffer based transaction, the xs structure is freed by the
process that initiated the transfer in scsi_scsi_cmd. In this case, an
explicit splbio/splx pair around the call to free_xs is required. Without
the splbio protection, the xs free list could be corrupted, and the type
driver's start routine might run without spl protection.
Submitted by: Tor Egge <Tor.Egge@idt.ntnu.no>
Obtained from: PR kern/2891
from last time. Some people have pointed out that there were some odd
side-effects in the changes I made. Two things are different:
- sc_print_addr() will print 'foodev0:' (i.e. sd0:, st0:, cd0:, etc...)
if the device name is known. If it's not known, it'll use a longer
notation. This shortens error messages back to a sane length.
- Added a small function called sc_print_init() to set the sc_printing
flag so that sc_print_addr() will know that we want it to print a
linefeed. Used this in scsi_device_attach() to restore proper carriage
return printing behavior which I broke.
Remaining bogons: the NCR SCSI driver prints out information while the
device-specific attach routine is running with its own linefeeds. This
breaks up the individual messages emitted by the subdriver modules and
causes at least one message to appear on a line by itself without a
device spec prefix. I'm not sure of the correct way to fix this, and
I don't have any NCR SCSI hardware to test with anyway.
There's probably more, but I gather that a rewrite of the SCSI subsystem
is pending anyway, so I'll leave the rest to Those Who Know More About
This Than I (tm).
("Hey! Who made _you_ the keeper of all things BSDish?!") but this has
bugged me for a long time, and now that I finally have the chance
to hack on it (and test the results), I'll take my chances. I can also
point to other BSD implementations for precedents if you put my back to
the wall.
The only thing that's changed is how the messages are formatted. Now,
instead of having this:
aha0 at 0x330-0x333 irq 11 drq 5 on isa
(aha0:3:0): "HP C1553A 9503" type 1 removable SCSI 2
st0(aha0:3:0): Sequential-Access density code 0x24, variable blocks, write-enabled
(aha0:3:1): "HP C1553A 9503" type 8 removable SCSI 2
ch0(aha0:3:1): Medium-Changer 6 slot(s) 1 drive(s) 0 arm(s) 0 i/e-slot(s)
We have this:
aha0 at 0x330-0x333 irq 11 drq 5 on isa
scbus0 at aha0 bus 0
st0 at scbus0 target 3 lun 0
st0: <HP C1553A 9503> type 1 removable SCSI 2
st0: Sequential-Access density code 0x24, variable blocks, write-enabled
ch0 at scbus0 target 3 lun 1
ch0: <HP C1553A 9503> type 8 removable SCSI 2
ch0: Medium-Changer 6 slot(s) 1 drive(s) 0 arm(s) 0 i/e-slot(s)
Which is (to me anyway) is a lot more pleasant to look at. (Call me
crazy -- g'head: you know you wanna -- but the previous messages remind
me of Linux. Ever see the output from the linux device probes? It's a mess
of copyright notices, version numbers/dates, author e-mail addresses and
other crap. Let's not go there, okay? Bleh.)
Notice that devices are now specified in terms of the scsi bus they
live on rather than the adapter. This better reflects the contents
of the kernel config file (if you use wired-down device specifications
anyway) and removes some ambiguity that may arise if you have a multi-
channel adapter with more than one bus.
Also, sc_print_addr() now generates messages like this:
st0 at scbus0 target 3 lun 0: NOT READY asc:3a,0 Medium not present
instead of this:
st0(aha0:3:0): NOT READY asc:3a,0 Medium not present
I also added a quirk entry for the HP Superstore 12000e 6 tape DAT
autoloader, which needs SC_MORE_LUS in order for the changer device
to be properly probed and attached. (I'm working on a chcontrol utility
to manipulate the changer on this drive which should hopefully be general
enough to work with other changers too. If you want the prototype I have
now, it's at ftp://skynet.ctr.columbia.edu/pub/freebsd/changer.c.)
Remaining bugs:
- The 'foodev0: yadda yadda yadda' bits should probably be printed entirely
by the device-specific subdriver attach code instead of half by the
scsi_device_attach() routine and half by the device specific attach
routine like it is now.
- The wired-down device specifications in the kernel config file should
be used to control bus/device probing to some extent rather than just
for choosing names for devices we find. If the config says there's a
device at scbus0 target 0 lun 0 called sd0, we should look there and
check for a device that can be managed by the sd driver. If we don't
find one, we should probably complain that there's no device there or
that there is a device but of the wrong type. Once all the devices from
the wired down list have been probed, the code can then autodetect and
autoattach any devices that remain unassigned.
- Apparently some tape changers (hi Ulf!) return 'not ready/medium not
present' when the magazine is loaded but a tape has not been put in the
drive yet. This causes an open(/dev/ch0) to fail and prevents you from
using the changer.c utility to load the first tape into the drive. My
HP changer does not behave this way. The workaround is to manually load
a tape into the drive before attempting to use the changer program, but
you can get in trouble if you accidentally eject a tape without loading
a new one and you're at a remote location: you won't be able to load
any tapes anymore. I'm not sure what the correct software solution is
for this but ideally there should be one.
- I should not be doing this: I'm the NIS guru, not the SCSI guru.
(This is not my beautiful code. How did I get here? My god: what
have I done?)
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
error code with ASC/ASCQ 4/1 (``Logical unit is in the process of
becoming ready'') non-fatal. Retry the operation until it will
eventually either yield a real error condition, or finally succeed.
Devices like CD changers or tape drives with a freshly inserted
cartridge should benefit from this.
Should go into 2.2 after some testing in -current. I'd like to see
this in the release if possible.
Unstaticize a function in scsi/scsi_base that was used, with an undocumented
option.
My last count on the LINT kernel shows:
Total symbols: 3647
unref symbols: 463
undef symbols: 4
1 ref symbols: 1751
2 ref symbols: 485
Approaching the pain threshold now.
o don't use polled mode after the device probe phase
o don't biodone() a NULL buffer pointer
o increase the timeout for scsi_read_capacity(); WORMs are slooow
o make WORMMs known to scsiconf at all
This brings the driver in a state where it at least doesn't
immediately panic, nor hangs the controller any more. Unfortunately,
at least the YAMAHA CDR100 i've been testing with answered my write
attempts with an "Incorrect command sequence" response. Perhaps other
CD burners might work however.
Reviewed by: dufault
for the kernel, but gcc provides an inline version of it if the
kernel is compiled with -O.
The inline memcmp() is OK for small compares and is better than
the dumb kernel bcmp() in all cases, but it has been hiding the
library memcmp() which is 4 times faster for large compares.
flags parameter to all xxstart routines so that the correct information can
be passed down into the device specific routines. This is needed to ensure
that ccb/scb allocation routines don't hang.
Submitted by: John Dyson
sd.c: Julian's removal of subdriver requests
st.c, scsi_tape.h: Julian's suport of compressed tape drives
Note: compressed tape drives are still not working fully.
scsiconf.h, scsi_base.c, scsi_driver.c: address problems in probes
and error console logs
tape drive. I traced it to sys/scsi/scsi_base.c where some code were added
to print the return values of the sense command. My tape drive returned a
extended flags value of 0x20, so the key that is the lower 4 bits, is 0.
The code uses "key-1" to index into a table and then the kernel go to never-
never land.
Here is a fix for this. Will somebody please apply it?
Submitted by: John Hay
Reenabled "SCIOCOMAND" ioctl.
Restructured so low level drivers can easily request retries.
Added preliminary fixed SCSI devices (should be revisited before 2.1)
Added "ssc" device that can have its' (HBA, ID, LUN) set via ioctl.
with BOUNCE_BUFFERS. This is more intuitive, and is better for future
multiplatform support. Added BOUNCE_BUFFERS option to the GENERIC and
LINT kernel config files.
in your kernel config now).
2) Added ps ddb function from 1.1.5. Cleaned it up a bit and moved into its
own file.
3) Added \r handing in db_printf.
4) Added missing memory usage stats to statclock().
5) Added dummy function to pseudo_set so it will be emitted if there
are no other pseudo declarations.
use of timeout_t -> timeout_func_t in aha1542 and aha1742 drivers.
2) fix a bug in the portalfs that was uncovered by better prototyping -
specifically, the time must be converted from timeval to timespec
before storing in va_atime.
3) fixed/added some miscellaneous prototypes
1) check va before clearing the page clean flag. Not doing so was
causing the vnode pager error 5 messages when paging from
NFS. (pmap.c)
2) put back interrupt protection in idle_loop. Bruce didn't think
it was necessary, John insists that it is (and I agree). (swtch.s)
3) various improvements to the clustering code (vm_machdep.c). It's
now enabled/used by default.
4) bad disk blocks are now handled properly when doing clustered IOs.
(wd.c, vm_machdep.c)
5) bogus bad block handling fixed in wd.c.
6) algorithm improvements to the pageout/pagescan daemons. It's amazing
how well 4MB machines work now.
>From: Adam David <adam@veda.is>
Subject: SCSI timeout in sdopen()
Date: Sun, 6 Feb 1994 21:40:48 GMT
Index: sys FreeBSD-current
Reference: FreeBSD-current/sys/9
Description:
sdopen() times out on slow SCSI devices. This code was moved into
a different file, which might explain why it got missed again.
Repeat-By:
using slow SCSI disks
cd.c:
Initialize channel info in CDIOCSETVOL ioctl.
Correct CDIOCSTOP and CDIOCEJCET ioctls to use scsi_stop_unit
instead of scsi_start_unit.
Add CDIOCALLOW and CDIOCPREVENT ioctls.
ch.h:
Return EBUSY instead of ENXIO if the device is already in use.
scsi_base.c:
Add scsi_stop_unit routine.
sd.c:
Add mising indirection through sc_link to sd_get_parms routine
when checking for media loaded.
st.c:
Return EBUSY instead of ENXIO if the device is already in use.
Clear the SDEV_WAITING flag in ststart if we do the wakeup call.
a binary link-kit. Make all non-optional options (pagers, procfs) standard,
and update LINT to reflect new symtab requirements.
NB: -Wtraditional will henceforth be forgotten. This editing pass was
primarily intended to detect any constructions where the old code might
have been relying on traditional C semantics or syntax. These were all
fixed, and the result of fixing some of them means that -Wall is now a
realistic possibility within a few weeks.
Here is the fix for the 'hanging' bug.
This bug happenned whenever two operations were already underway on the
disk and a third (non-IO) command was requested..
in this case the process submitting the NON-IO command was requested to wait,
and a flag set so that on completion of the IO commands, the Non-io command
was given priority over any pending IO commands. (the queue is not
allowed to drain while there are pending "special" ops).
The flag that indicated this was not being reset, so further IO commands
were prohibited from that moment on.
