Re: scsi: fix target reset handling

[Mike Christie <michaelc@cs.wisc.edu>]

Moore, Eric wrote:
> On Friday, February 29, 2008 5:25 PM,  Mike Christie wrote:
>> This patchset fixes the problem where scsi-ml will call the 
>> device reset
>> handler for each logical unit, but some drivers are sending a target
>> reset. Because we do not need to send a target reset multiple times,
>> this patchset creates a new target reset callout which of course is
>> called once per target instead of once per lu. It also cleans up
>> the all the commands sent to the target when SUCCESS is returned.
>>
>> qla4xxx, qla2xxx and lpfc were test with a hacked up sg_reset. I also
>> sent lots of commands to the target and decreased the cmd timeout to
>> 1 second so the scsi would run (turned off the eh abort callout too).
>>
>> The arm scsi, mpt fusion, sym53c8xx_2, and a100u2w, and qla1280
>> drivers were only compile tested, but looked like the only needed
>> a rename of the scsi eh handler.
>>
>> The zfcp driver is also only compile tested. It was doing a lun
>> reset and possibly target reset, so I split that up to use
>> the device and target reset handlers. scsi-ml will escalate from
>> the device to the target reset for the driver.
>>
>>
> 
> The fusion firmware supports Logical Unit Reset, so why not fix
> mptscsih_dev_reset so its passing
> MPI_SCSITASKMGMT_TASKTYPE_LOGICAL_UNIT_RESET, and lun number to
> mptscsih_TMHandler, and create the new function mptscsih_target_reset as
> you've done?
> 

I did not do this because I was not trying to add new functionality. I 
was just trying to fix what was there.

How about I add the LU reset support in a separate patch, so git revert 
will be kinder to me?

There was also some side discussion about side affects of doing a lu 
reset and if we need to be doing something more than what we do today 
from the device reset handler, so I did not want to dig into that in 
this patchset. I am just trying to get target reset done in the proper 
place on this pass. In later patches I want to tackle TMFs like lu 
reset, abort task set, etc.