Re: [PATCH 7/8] Psmouse - add packet size

[Dmitry Torokhov <dtor_core@ameritech.net>]

On Wednesday 29 September 2004 02:15 am, Vojtech Pavlik wrote:
> On Wed, Sep 29, 2004 at 01:47:34AM -0500, Dmitry Torokhov wrote:
> 
> > -int alps_detect(struct psmouse *psmouse)
> > +int alps_detect(struct psmouse *psmouse, int set_properties)
> >  {
> > -	return alps_get_model(psmouse) < 0 ? 0 : 1;
> > +	if (alps_get_model(psmouse) < 0)
> > +		return 0;
> > +
> > +	if (set_properties) {
> > +		psmouse->vendor = "ALPS";
> > +		psmouse->name = "TouchPad";
> > +	}
> > +	return 1;
> >  }
> 
> I think we should return -1 (or -errno) on failure and 0 on success,
> like everybody else does.
>

All *detect functions return boolean value - either the device was detected or
not. I think it makes most sense. Negative error is convenient when function
normally returns some other meaningful value, like length. *detect is a simple
yes/no question, it is not really an error at all.
  
> 
> This should be:
> 
> 	if (param[0] != 3) 
> 		return -1;
> 	if (set_properties) {
> 		set_bit(REL_WHEEL, psmouse->dev.relbit);
> 		if (!psmouse->vendor) psmouse->vendor = "Generic";
> 		if (!psmouse->name) psmouse->name = "Wheel Mouse";
> 		psmouse->pktsize = 4;
> 	}
> 	return 0;
> 
> ... and similarly elsewhere. You save one level of nesting and it makes
> more sense.
> 

Ok, will change.

-- 
Dmitry