Re: Return of PENDING status to SCSI driver

Alan Stern
2009-06-15T14:49:31Z

On Mon, 15 Jun 2009, Boaz Harrosh wrote:

> You are right, this is not what I understood. I understood that he is hacking
> on current USB driver to try and enhance it in such a way that it will support
> command queuing at the target.
>
> He is not currently concerned about any devices but his own HW. But he is certainly
> not writing a driver from scratch. He is basing on the current code base.
>
> Did I understand right?

It's hard to tell from what he wrote. Ramya's description of his code
is not very complete or precise.

> Do you think you have any tips for him. For example at the USB transport side,
> what is needed for asynchronous command execution as opposed to what is done now?

Nothing extra is needed as far as the lower parts of the USB stack are
concerned; they already are fully asynchronous. But the entire
transport mechanism of usb-storage would have to be rewritten, since it
runs in a single thread and always waits for one command to finish
before accepting a new command.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html