Re: [PATCH -next v2 1/2] device property: Return -ENXIO if there is no suitable FW interface

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Wednesday, August 26, 2015 04:25:59 PM Guenter Roeck wrote:
> On 08/26/2015 04:37 PM, Rafael J. Wysocki wrote:
> > On Wednesday, August 26, 2015 01:20:44 PM Guenter Roeck wrote:
> >> Return -ENXIO if device property array access functions don't find
> >> a suitable firmware interface.
> >>
> >> This lets drivers decide if they should use available platform data
> >> instead.
> >>
> >> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> >> ---
> >> v2: Added patch
> >>
> >>   drivers/base/property.c | 7 +++++++
> >>   1 file changed, 7 insertions(+)
> >>
> >> diff --git a/drivers/base/property.c b/drivers/base/property.c
> >> index 287704d680bf..9600b824d138 100644
> >> --- a/drivers/base/property.c
> >> +++ b/drivers/base/property.c
> >> @@ -69,6 +69,9 @@ static int pset_prop_read_array(struct property_set *pset, const char *name,
> >>   	struct property_entry *prop;
> >>   	unsigned int item_size;
> >>
> >> +	if (!pset)
> >> +		return -ENXIO;
> >> +
> >
> > This isn't exactly straightforward, because it relies on the fact that
> > pset_prop_read_array() is the last thing tried by FWNODE_PROP_READ_ARRAY()
> > and fwnode_property_read_string_array().  A comment about that might be
> > helpful.
> >
> I see two options: Add a comment above, or change the calling code to
> 
> 	...
> 	else if (is_pset(fwnode))
> 		return pset_prop_read_array(to_pset(fwnode), propname,
>                           	            DEV_PROP_STRING, val, nval);
> 	return -ENXIO;
> 
> which would make it obvious and avoid side effects if the code is changed
> later on. Would you be ok with this ?

The second option is obviously cleaner to me and I prefer cleaner code. :-)

Thanks,
Rafael