netdev - Re: [PATCH v2 1/2] platform: make platform_get_irq

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Date:   Mon, 14 Feb 2022 12:13:01 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
Cc:     Sergey Shtylyov <s.shtylyov@....ru>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org, Andrew Lunn <andrew@...n.ch>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Vignesh Raghavendra <vigneshr@...com>,
        Jiri Slaby <jirislaby@...nel.org>, linux-iio@...r.kernel.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Amit Kucheria <amitk@...nel.org>, alsa-devel@...a-project.org,
        Liam Girdwood <lgirdwood@...il.com>,
        linux-phy@...ts.infradead.org,
        Thierry Reding <thierry.reding@...il.com>,
        linux-mtd@...ts.infradead.org, linux-i2c@...r.kernel.org,
        linux-gpio@...r.kernel.org,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Guenter Roeck <groeck@...omium.org>, linux-spi@...r.kernel.org,
        Lee Jones <lee.jones@...aro.org>,
        openipmi-developer@...ts.sourceforge.net,
        Peter Korsgaard <peter@...sgaard.com>,
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        Matthias Schiffer <matthias.schiffer@...tq-group.com>,
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        Richard Weinberger <richard@....at>,
        Bartosz Golaszewski <brgl@...ev.pl>,
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        Mun Yew Tham <mun.yew.tham@...el.com>,
        Eric Auger <eric.auger@...hat.com>, netdev@...r.kernel.org,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
        Cornelia Huck <cohuck@...hat.com>, linux-mmc@...r.kernel.org,
        Joakim Zhang <qiangqing.zhang@....com>,
        Oleksij Rempel <linux@...pel-privat.de>,
        linux-renesas-soc@...r.kernel.org, Vinod Koul <vkoul@...nel.org>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Niklas Söderlund 
        <niklas.soderlund@...natech.se>,
        Brian Norris <computersforpeace@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH v2 1/2] platform: make platform_get_irq_optional()
 optional

On Mon, Feb 14, 2022 at 08:13:51AM +0100, Uwe Kleine-König wrote:
> 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@...tq-group.com>
> > Signed-off-by: Sergey Shtylyov <s.shtylyov@....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.)

I think you haven't reacted anyhow to my point that you mixing apples and
bananas together when comparing this 0 to the others _optional APIs.

> 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.


-- 
With Best Regards,
Andy Shevchenko