Re: [PATCH] [V2] powerpc: Xilinx: PS2: Added new XPS PS2 driver

[Grant Likely <grant.likely@secretlab.ca>]

On Thu, Jul 03, 2008 at 01:27:00PM -0400, Dmitry Torokhov wrote:
> Hi John,
> 
> On Thu, Jul 03, 2008 at 09:42:31AM -0700, John Linn wrote:
> > +
> > +	/* Initialize the PS/2 interface */
> > +	mutex_lock(&drvdata->cfg_mutex);
> > +	if (xps2_initialize(drvdata)) {
> > +		mutex_unlock(&drvdata->cfg_mutex);
> > +		dev_err(dev, "Could not initialize device\n");
> > +		retval = -ENODEV;
> > +		goto failed3;
> > +	}
> > +	mutex_unlock(&drvdata->cfg_mutex);
> 
> The drvdata is allocated per-port and so both (there are 2 PS/2 ports,
> right?) ports get their own copy of cfg_mutex. Since you are trying to
> serialze access to resource shared by both ports it will not work.
> The original driver-global mutex was appropriate (the only thing I
> objected there was use of a counting semaphore instead of a mutex).

John, correct me if I'm wrong, but I don't think there are any shared
resources being accessed here and I believe the mutex is entirely
unnecessary.

Cheers,
g.