Hi Petr,
On Thu, Mar 28, 2019 at 03:29:27PM +0100, Petr Mladek wrote:
> On Tue 2019-03-26 15:24:50, Andy Shevchenko wrote:
> > On Tue, Mar 26, 2019 at 02:11:35PM +0100, Rasmus Villemoes wrote:
> > > On 26/03/2019 13.41, Sakari Ailus wrote:
> > > > Add support for %pfw conversion specifier (with "f" and "P" modifiers) to
> > > > support printing full path of the node, including its name ("f") and only
> > > > the node's name ("P") in the printk family of functions. The two flags
> > > > have equivalent functionality to existing %pOF with the same two modifiers
> > > > ("f" and "P") on OF based systems. The ability to do the same on ACPI
> > > > based systems is added by this patch.
> >
> > > > + for (pass = false; strspn(fmt, modifiers); fmt++, pass = true) {
> > > > + if (pass) {
> > > > + if (buf < end)
> > > > + *buf = ':';
> > > > + buf++;
> > > > + }
> > > > +
> > > > + switch (*fmt) {
> > > > + case 'f': /* full_name */
> > > > + buf = fwnode_gen_full_name(fwnode, buf, end);
> > > > + break;
> > > > + case 'P': /* name */
> > > > + buf = string(buf, end, fwnode_get_name(fwnode),
> > > > + str_spec);
> > > > + break;
> > > > + default:
> > > > + break;
> > > > + }
> > > > + }
> > >
> > > This seems awfully complicated. Why would anyone ever pass more than one
> > > of 'f' and 'P'? Why not just
> > >
> > > switch(*fmt) {
> > > case 'P':
> > > ...
> > > case 'f':
> > > default:
> > > ...
> > > }
> > >
> > > which avoids the loop and the strcspn. Or, drop the default: case and
> > > don't have logic at all for falling back to 'f' if neither is present.
> > >
> > > > + return widen_string(buf, buf - buf_start, end, spec);
> > > > +}
> >
> > My point as well (as per sent comments against previous version).
> > Sakari, can you add test cases at the same time?
> >
> > > > return device_node_string(buf, end, ptr, spec, fmt + 1);
> >
> > > > + return fwnode_string(buf, end, ptr, spec, fmt + 1);
> > >
> > > Why not pass fmt+2; we know that fmt+1 points at a 'w'. Just to avoid
> > > doing the fmt++ inside fwnode_string().
> >
> > I guess in order to be consistent with existing %pOF case. But wouldn't be
> > better to fix %pOF for that sooner or later?
>
> Good question. Are there any %pOF users that would want to use the for
> cycle and printk more values by single %pOF? Would the output be human
> readable without any delimiters or words around?
The delimiter is ':'. What comes to users, quick grepping tells the only
users are actually the unit tests, and this is also present in the
documentation.
Based on that I think we can safely omit that on %pfw actually. I thought
it was actually used somewhere.
--
Kind regards,
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
