On Tue, May 23, 2017 at 11:47:06PM +0200, Micha?? K??pie?? wrote:
> > On Fri, May 19, 2017 at 09:44:45AM +0200, Micha?? K??pie?? wrote:
> > > It is easier to simply store a module-wide
> > > pointer to the last (most likely only) FUJ02E3 ACPI device found, make
> > > the aforementioned API use it and cover our bases by warning the user if
> > > firmware exposes multiple FUJ02E3 ACPI devices.
> > > :
> > > @@ -788,6 +789,9 @@ static int acpi_fujitsu_laptop_add(struct acpi_device *device)
> > > if (!priv)
> > > return -ENOMEM;
> > >
> > > + WARN_ONCE(fext, "More than one FUJ02E3 ACPI device was found. Driver may not work as intended.");
> > > + fext = device;
> > > +
> > > fujitsu_laptop = priv;
> > > fujitsu_laptop->acpi_handle = device->handle;
> > > sprintf(acpi_device_name(device), "%s",
> >
> > I thought WARN_ONCE() printed the warning when it was encountered for the
> > first time and then suppressed it on all other occasions.
>
> Correct.
>
> > If this is true
> > then we'll get the warning even when there is only one FUJ02E3 in the
> > system. Am I missing something?
>
> Probably the fact that the first argument of the macro is a conditional
> expression ...
Ah (having now had an opportunity to look at the source of WARN_ONCE()),
it's tested within WARN_ONCE.
> ("fext" is functionally equivalent to "fext != NULL" in this case).
Indeed, by virtue of the test done in WARN_ONCE(). Ok, that makes sense.
Regards
jonathan
