Re: [usb-storage] Re: [PATCH 04/14] uas: lock the abort handler

[Oliver Neukum <oneukum-IBi9RG/b67k@public.gmane.org>]

On Tue, 2016-01-26 at 10:28 -0500, Alan Stern wrote:
> On Tue, 26 Jan 2016, Oliver Neukum wrote:

> > That is problematic. The ABORT_TMF does need IO for which we need
> > to wait. And if we just submit and pretend the abort worked, the tag
> > will be reused.
> > Perhaps we could drop the spinlock. I think it is time to talk to
> > the SCSI people.
> 
> The abort handler doesn't have to wait for the command to terminate.  
> It merely has to initiate an abort and return.  The SCSI layer gets 
> notified via the usual mechanism when the command eventually finishes, 
> whether it was successful or not.

This is stange. I don't see how we can guarantee a command completion
if eh_abort_handler() has sent the TMF.
It was my understanding that returning from eh_abort_handler()
means that a tag is considered free again and will be reused.
Could you clarify?

	Regards
		Oliver



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