Re: [Qemu-devel] [PATCH v2] lsi: Reselection needed to remove pending commands from queue

[George Kennedy <george.kennedy@oracle.com>]

On 10/23/2018 6:31 PM, Paolo Bonzini wrote:
> On 24/10/2018 00:11, George Kennedy wrote:
>>> What about "req->hba_private != s->current"?  That should cause a call
>>> to lsi_queue_req, and then you can check s->want_resel in lsi_queue_req.
>> For the extended period of time where lsi_queue_req() is not being
>> called from lsi_transfer_data(), my debug shows "s->waiting" is not "1"
>> and req->hba_private is equal to s->current.
> That would mean indeed that no reselection is needed---but that's wrong.
>
> Why didn't lsi_do_command invoke lsi_queue_command?  That would set
> s->current to NULL (on the SCSI level, that means the bus is freed; on
> the QEMU level, the idea is that lsi_transfer_data would then start a
> reselection).

Through the extended period of time with no call to lsi_reselect(), the 
check of "s->command_complete" in lsi_do_command() is always "1" and 
therefore no call to lsi_queue_command() occurs.

"s->command_complete" is set to "1" in lsi_transfer_data().

>
> Thanks,
>
> Paolo
>
>> req->hba_private is set to NULL in lsi_command_complete() and that's
>> where I tried to add a call to lsi_reselect(), but the Scripts are not
>> in the correct state to allow the call.
>>
>> lsi_transfer_data() or lsi_command_complete() are probably the 2
>> potential places where a fix could be added if the Script state would
>> allow it.
>