Re: [PATCH v2 net-next 6/9] sunvnet: straighten up message event handling logic

[Shannon Nelson]

On 2/8/2017 7:59 AM, Sowmini Varadhan wrote:
> On (02/07/17 14:12), Shannon Nelson wrote:
> > +
> > +	/* we don't expect any other bits */
> > +	BUG_ON(port->rx_event & ~(LDC_EVENT_DATA_READY |
> > +				  LDC_EVENT_RESET |
> > +				  LDC_EVENT_UP));
> > +
> > +	/* RESET takes precedent over any other event */
> > +	if (port->rx_event & LDC_EVENT_RESET) {
>                   :
> >  		port->rx_event = 0;
> >  		return 0;
> >  	}
> > +	if (port->rx_event & LDC_EVENT_UP) {
> > +		vio_link_state_change(vio, LDC_EVENT_UP);
> > +		port->rx_event = 0;
> > +		return 0;
> > +	}
> >
> >  	err = 0;
> >  	tx_wakeup = 0;
>
> IIRC there were timing-related situations where you can get woken up with
> both UP and DATA_READY, and if my reading of your patch is
> correct, we would ignore the DATA_READY, and return, right?
>
> --Sowmini

The existing code does this as well - if it first finds a RESET, it 
handles it then hits the return 0.  Next if it finds the UP, it does the 
goto back to the ldc_ctrl: to process, and hits the same return 0.  Only 
if neither of these bits have been seen does the code move on to process 
the DATA_READY event.

If we're seeing cases of both UP and DATA_READY, then yes we'll wnat to 
look at changing this logic.  I think that should be a separate patch.

sln