[PATCH v2 1/2] platform: make platform_get_irq_optional() optional

[Uwe Kleine-König]

On Sat, Feb 12, 2022 at 11:16:30PM +0300, Sergey Shtylyov wrote:
> This patch is based on the former Andy Shevchenko's patch:
> 
> https://lore.kernel.org/lkml/20210331144526.19439-1-andriy.shevchenko@linux.intel.com/
> 
> Currently platform_get_irq_optional() returns an error code even if IRQ
> resource simply has not been found.  It prevents the callers from being
> error code agnostic in their error handling:
> 
> 	ret = platform_get_irq_optional(...);
> 	if (ret < 0 && ret != -ENXIO)
> 		return ret; // respect deferred probe
> 	if (ret > 0)
> 		...we get an IRQ...
> 
> All other *_optional() APIs seem to return 0 or NULL in case an optional
> resource is not available.  Let's follow this good example, so that the
> callers would look like:
> 
> 	ret = platform_get_irq_optional(...);
> 	if (ret < 0)
> 		return ret;
> 	if (ret > 0)
> 		...we get an IRQ...
> 
> Reported-by: Matthias Schiffer <matthias.schiffer at ew.tq-group.com>
> Signed-off-by: Sergey Shtylyov <s.shtylyov at omp.ru>

While this patch is better than v1, I still don't like it for the
reasons discussed for v1. (i.e. 0 isn't usable as a dummy value which I
consider the real advantage for the other _get_optional() functions.)

Apart from that, I think the subject is badly chosen. With "Make
somefunc() optional" I would expect that you introduce a Kconfig symbol
that results in the function not being available when disabled.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |
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