Re: [PATCH V6 3/7] device property: Introduce a common API to fetch device match data

[Rafael J. Wysocki]

On Thu, Dec 7, 2017 at 11:06 PM, Sakari Ailus <sakari.ailus@xxxxxx> wrote:
> On Thu, Dec 07, 2017 at 03:17:52PM -0500, Sinan Kaya wrote:
>> On 12/7/2017 7:40 AM, Sakari Ailus wrote:
>> > On Tue, Dec 05, 2017 at 12:04:48PM -0500, Sinan Kaya wrote:
>> >> @@ -101,6 +103,8 @@ struct fwnode_operations {
>> >>    (*graph_get_port_parent)(struct fwnode_handle *fwnode);
>> >>    int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
>> >>                                struct fwnode_endpoint *endpoint);
>> >> +  void *(*get_match_data)(const struct fwnode_handle *fwnode,
>> >> +                          struct device *dev);
>> >
>> > You can make dev const, too.
>> >
>>
>> done, I couldn't change device_get_match_data() parameter const due to
>> dev_fwnode() function.
>>
>>                  from /local/mnt/workspace/projects/caf/kernel/drivers/base/property.c:13:
>>
>> /local/mnt/workspace/projects/caf/kernel/drivers/base/property.c:1341:39: warning: passing argument 1 of 'dev_fwnode' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>>   return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data,
>
> Right. Makes sense.
>
> I guess it's not perhaps worth it introducing dev_fwnode_const just for
> this. devices are seldom if ever const anyway.

They cannot be const.  Had they been const, it wouldn't have been
possible to register them even. :-)