Re: [PATCH 06/20] include: input: elan-i2c-ids: Mark 'elan_acpi_id' as __maybe_unused

[Lee Jones]

On Thu, 05 Nov 2020, Dmitry Torokhov wrote:

> On Thu, Nov 05, 2020 at 09:13:05AM +0000, Lee Jones wrote:
> > On Wed, 04 Nov 2020, Dmitry Torokhov wrote:
> > 
> > > Hi Lee,
> > > 
> > > On Wed, Nov 04, 2020 at 04:24:13PM +0000, Lee Jones wrote:
> > > > Some drivers which include 'elan-i2c-ids.h' make use of
> > > > 'elan_acpi_id', but not all do.  Tell the compiler that this is
> > > > expected behaviour.
> > > > 
> > > > Fixes the following W=1 kernel build warning(s):
> > > > 
> > > >  include/linux/input/elan-i2c-ids.h:26:36: warning: ‘elan_acpi_id’ defined but not used [-Wunused-const-variable=]
> > > > 
> > > > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > > > Cc: dusonlin@xxxxxxxxxx
> > > > Cc: KT Liao <kt.liao@xxxxxxxxxx>
> > > > Cc: linux-input@xxxxxxxxxxxxxxx
> > > > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> > > > ---
> > > >  include/linux/input/elan-i2c-ids.h | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/include/linux/input/elan-i2c-ids.h b/include/linux/input/elan-i2c-ids.h
> > > > index 520858d126808..b6976d99b6b75 100644
> > > > --- a/include/linux/input/elan-i2c-ids.h
> > > > +++ b/include/linux/input/elan-i2c-ids.h
> > > > @@ -23,7 +23,7 @@
> > > >  
> > > >  #include <linux/mod_devicetable.h>
> > > >  
> > > > -static const struct acpi_device_id elan_acpi_id[] = {
> > > > +static const struct acpi_device_id __maybe_unused elan_acpi_id[] = {
> > > >  	{ "ELAN0000", 0 },
> > > >  	{ "ELAN0100", 0 },
> > > >  	{ "ELAN0600", 0 },
> > > 
> > > I think I'd prefer something like this instead:
> > > 
> > > diff --git a/drivers/input/mouse/elan_i2c_core.c
> > > b/drivers/input/mouse/elan_i2c_core.c
> > > index c599e21a8478..65d21a050cea 100644
> > > --- a/drivers/input/mouse/elan_i2c_core.c
> > > +++ b/drivers/input/mouse/elan_i2c_core.c
> > > @@ -34,7 +34,6 @@
> > >  #include <linux/completion.h>
> > >  #include <linux/of.h>
> > >  #include <linux/property.h>
> > > -#include <linux/input/elan-i2c-ids.h>
> > >  #include <linux/regulator/consumer.h>
> > >  #include <asm/unaligned.h>
> > > 
> > > @@ -1413,6 +1412,7 @@ static const struct i2c_device_id elan_id[] = {
> > >  MODULE_DEVICE_TABLE(i2c, elan_id);
> > > 
> > >  #ifdef CONFIG_ACPI
> > > +#include <linux/input/elan-i2c-ids.h>
> > >  MODULE_DEVICE_TABLE(acpi, elan_acpi_id);
> > >  #endif
> > 
> > Moving an #include file to the bottom of a source file, really?
> > 
> > I can do as you wish, but it's a pretty 'interesting' solution. :)
> 
> I see absolutely nothing wrong with it, and if you check kernel sources
> you will see #includes used this way.
> 
> What is your concern?

I guess just the unfamiliarity of it.

It's the first time I've seen such a solution.

Will fix.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
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