Re: [PATCH 1/1] driver: Tpm hardware enablement

[Alan Cox]

On Iau, 2004-12-09 at 15:48, Arjan van de Ven wrote:
> > +	/* wait for status */
> > +	add_timer(&status_timer);
> > +	do {
> > +		schedule();
> > +		status = inb(chip->base + NSC_STATUS);
> > +		if (status & NSC_STATUS_OBF)
> > +			status = inb(chip->base + NSC_DATA);
> > +		if (status & NSC_STATUS_RDY) {
> > +			del_singleshot_timer_sync(&status_timer);
> > +			return 0;
> > +		}
> > +	} while (!expired);
> 
> same comment. Also the timer handling looks suspect... can you guarantee
> 100% sure that the timer is gone when the while falls through ?

Yes but you can't be sure it ever will - needs an "rmb()" barrier so
that the compiler doesn't sneak off and optimise expired


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