In a second step of the driver development, the following improvement has
been applied: The first approach limited the number of devices to 7, far
- fewer than the 15 that it could usem then it just maped ldn ->
+ fewer than the 15 that it could use, then it just mapped ldn ->
(ldn/8,ldn%8) for pun,lun. We ended up with a real mishmash of puns
and luns, but it all seemed to work.
device to be existant, but it has no ldn assigned, it gets a ldn out of 7
to 14. The numbers are assigned in cyclic order. Therefore it takes 8
dynamical reassignments on the SCSI-devices, until a certain device
- loses its ldn again. This assures, that dynamical remapping is avoided
+ loses its ldn again. This assures that dynamical remapping is avoided
during intense I/O between up to 15 SCSI-devices (means pun,lun
- combinations). A further advantage of this method is, that people who
+ combinations). A further advantage of this method is that people who
build their kernel without probing on all luns will get what they expect,
because the driver just won't assign everything with lun>0 when
- multpile lun probing is inactive.
+ multiple lun probing is inactive.
2.4 SCSI-Device Order
---------------------
2.6 Abort & Reset Commands
--------------------------
These are implemented with busy waiting for interrupt to arrive.
- ibmmca_reset() and ibmmca_abort() do not work sufficently well
- up to now and need still a lot of development work. But, this seems
- to be even a problem with other SCSI-low level drivers, too. However,
+ ibmmca_reset() and ibmmca_abort() do not work sufficiently well
+ up to now and need still a lot of development work. This seems
+ to be a problem with other low-level SCSI drivers too, however
this should be no excuse.
2.7 Disk Geometry
not like sending commands to non-existing SCSI-devices and will react
with a command error as a sign of protest. While this error is not
present on IBM SCSI Adapter w/cache, it appears on IBM Integrated SCSI
- Adapters. Therefore, I implemented a workarround to forgive those
- adapters their protests, but it is marked up in the statisctis, so
+ Adapters. Therefore, I implemented a workaround to forgive those
+ adapters their protests, but it is marked up in the statistics, so
after a successful boot, you can see in /proc/scsi/ibmmca/<host_number>
how often the command errors have been forgiven to the SCSI-subsystem.
If the number is bigger than 0, you have a SCSI subsystem of older
not accept this, as they stick quite near to ANSI-SCSI and report
a COMMAND_ERROR message which causes the driver to panic. The main
problem was located around the INQUIRY command. Now, for all the
- mentioned commands, the buffersize, sent to the adapter is at
+ mentioned commands, the buffersize sent to the adapter is at
maximum 255 which seems to be a quite reasonable solution.
- TEST_UNIT_READY gets a buffersize of 0 to make sure, that no
+ TEST_UNIT_READY gets a buffersize of 0 to make sure that no
data is transferred in order to avoid any possible command failure.
- 2) On unsuccessful TEST_UNIT_READY, the midlevel-driver has to send
- a REQUEST_SENSE in order to see, where the problem is located. This
+ 2) On unsuccessful TEST_UNIT_READY, the mid-level driver has to send
+ a REQUEST_SENSE in order to see where the problem is located. This
REQUEST_SENSE may have various length in its answer-buffer. IBM
- SCSI-subsystems report a command failure, if the returned buffersize
- is different from the sent buffersize, but this can be supressed by
+ SCSI-subsystems report a command failure if the returned buffersize
+ is different from the sent buffersize, but this can be suppressed by
a special bit, which is now done and problems seem to be solved.
2) Code adaption to all kernel-releases. Now, the 3.2 code compiles on
2.0.x, 2.1.x, 2.2.x and 2.3.x kernel releases without any code-changes.
Q: "Reset SCSI-devices at boottime" halts the system at boottime, why?
A: This is only tested with the IBM SCSI Adapter w/cache. It is not
- yet prooved to run on other adapters, however you may be lucky.
+ yet proven to run on other adapters, however you may be lucky.
In version 3.1d this has been hugely improved and should work better,
now. Normally you really won't need to activate this flag in the
kernel configuration, as all post 1989 SCSI-devices should accept
The parameter 'normal' sets the new industry standard, starting
from pun 0, scanning up to pun 6. This allows you to change your
opinion still after having already compiled the kernel.
- Q: Why I cannot find the IBM MCA SCSI support in the config menue?
+ Q: Why can't I find IBM MCA SCSI support in the config menu?
A: You have to activate MCA bus support, first.
Q: Where can I find the latest info about this driver?
A: See the file MAINTAINERS for the current WWW-address, which offers
Guide) what has to be done for reset, we still share the bad shape of
the reset functions with all other low level SCSI-drivers.
Astonishingly, reset works in most cases quite ok, but the harddisks
- won't run in synchonous mode anymore after a reset, until you reboot.
+ won't run in synchronous mode anymore after a reset, until you reboot.
Q: Why does my XXX w/Cache adapter not use read-prefetch?
A: Ok, that is not completely possible. If a cache is present, the
adapter tries to use it internally. Explicitly, one can use the cache
git.samba.org / sfrench / cifs-2.6.git / blobdiff