Re: [PATCH 01/18] ide: dequeue in-flight request

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Friday 08 May 2009 04:53:59 Tejun Heo wrote:
> ide generally has single request in flight and tracks it using
> hwif->rq and all state handlers follow the following convention.
> 
> * ide_started is returned if the request is in flight.
> 
> * ide_stopped is returned if the queue needs to be restarted.  The
>   request might or might not have been processed fully or partially.
> 
> * hwif->rq is set to NULL, when an issued request completes.
> 
> So, dequeueing model can be implemented by dequeueing after fetch,
> requeueing if hwif->rq isn't NULL on ide_stopped return and doing
> about the same thing on completion / port unlock paths.  These changes
> can be made in ide-io proper.
> 
> In addition to the above main changes, the following updates are
> necessary.
> 
> * ide-cd shouldn't dequeue a request when issuing REQUEST SENSE for it
>   as the request is already dequeued.
> 
> * ide-atapi uses request queue as stack when issuing REQUEST SENSE to
>   put the REQUEST SENSE in front of the failed request.  This now
>   needs to be done using requeueing.
> 
> [ Impact: dequeue in-flight request ]
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> Cc: Borislav Petkov <petkovbb@googlemail.com>
> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>

Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>