Re: Question about hwmon_attr_show_string

Guenter Roeck
2017-03-06T23:49:52Z

On Mon, Mar 06, 2017 at 09:48:35PM +0100, Peter Hüwe wrote:
> Hi Guenter,
>
> I was wondering whether there was a particular reason why
> hwmon_attr_show_string passes only an "empty" pointer(pointer) to the ops-
> >read_string function rather than the buffer itself?
>
> Wouldn't this mean that in ops->read_string I'd have to reserve some space for
> the value on the heap (and taking care to free it somewhere, since returning
> an address on the stack is bad idea), instead of calling sprintf(buf, "%s\n",
> s) directly?
>
> With the current implementation I have to sprintf it into my local buffer and
> you sprintf it again into the final buffer.
>
The idea was that the called code would return a pointer to a constant string,
ie one that isn't changing from call to call.

What attribute do you see that would require a dynamic (changing) string ?

Thanks,
Guenter