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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <fabb8166-e3a9-c48e-073b-cdbbe8c62714@omp.ru>
Date:   Wed, 19 Jan 2022 22:49:52 +0300
From:   Sergey Shtylyov <s.shtylyov@....ru>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
CC:     Andrew Lunn <andrew@...n.ch>, Ulf Hansson <ulf.hansson@...aro.org>,
        Vignesh Raghavendra <vigneshr@...com>,
        KVM list <kvm@...r.kernel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        <linux-iio@...r.kernel.org>,
        "Linus Walleij" <linus.walleij@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        "ALSA Development Mailing List" <alsa-devel@...a-project.org>,
        Jaroslav Kysela <perex@...ex.cz>,
        Guenter Roeck <groeck@...omium.org>,
        Thierry Reding <thierry.reding@...il.com>,
        MTD Maling List <linux-mtd@...ts.infradead.org>,
        Linux I2C <linux-i2c@...r.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        <linux-phy@...ts.infradead.org>, <netdev@...r.kernel.org>,
        linux-spi <linux-spi@...r.kernel.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        Khuong Dinh <khuong@...amperecomputing.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Matthias Schiffer <matthias.schiffer@...tq-group.com>,
        Kamal Dasu <kdasu.kdev@...il.com>,
        Lee Jones <lee.jones@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        "Kishon Vijay Abraham I" <kishon@...com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        "open list:SERIAL DRIVERS" <linux-serial@...r.kernel.org>,
        bcm-kernel-feedback-list <bcm-kernel-feedback-list@...adcom.com>,
        Zhang Rui <rui.zhang@...el.com>,
        <platform-driver-x86@...r.kernel.org>,
        Linux PWM List <linux-pwm@...r.kernel.org>,
        Robert Richter <rric@...nel.org>,
        "Saravanan Sekar" <sravanhome@...il.com>,
        Corey Minyard <minyard@....org>,
        Linux PM list <linux-pm@...r.kernel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        "Mauro Carvalho Chehab" <mchehab@...nel.org>,
        John Garry <john.garry@...wei.com>,
        Takashi Iwai <tiwai@...e.com>,
        Peter Korsgaard <peter@...sgaard.com>,
        "William Breathitt Gray" <vilhelm.gray@...il.com>,
        Mark Gross <markgross@...nel.org>,
        Hans de Goede <hdegoede@...hat.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Mark Brown <broonie@...nel.org>,
        "Borislav Petkov" <bp@...en8.de>, Jakub Kicinski <kuba@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        <openipmi-developer@...ts.sourceforge.net>,
        "Benson Leung" <bleung@...omium.org>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        <linux-edac@...r.kernel.org>, Tony Luck <tony.luck@...el.com>,
        "Richard Weinberger" <richard@....at>,
        Mun Yew Tham <mun.yew.tham@...el.com>,
        "Eric Auger" <eric.auger@...hat.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
        Cornelia Huck <cohuck@...hat.com>,
        "Linux MMC List" <linux-mmc@...r.kernel.org>,
        Joakim Zhang <qiangqing.zhang@....com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux-Renesas <linux-renesas-soc@...r.kernel.org>,
        Vinod Koul <vkoul@...nel.org>,
        "James Morse" <james.morse@....com>,
        Zha Qipeng <qipeng.zha@...el.com>,
        "Sebastian Reichel" <sre@...nel.org>,
        Niklas Söderlund <niklas.soderlund@...natech.se>,
        <linux-mediatek@...ts.infradead.org>,
        "Brian Norris" <computersforpeace@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH 1/2] platform: make platform_get_irq_optional() optional

On 1/19/22 9:58 PM, Andy Shevchenko wrote:

[...]
>> Because with your change we have:
>>
>>  - < 0 -> error
>>  - == 0 -> no irq
>>  - > 0 -> irq
>>
>> For my part I'd say this doesn't justify the change, but at least I
>> could better life with the reasoning. If you start at:
>>
>> 	irq = platform_get_irq_optional(...)
>> 	if (irq < 0 && irq != -ENXIO)
>> 		return irq
>> 	else if (irq > 0)
>> 		setup_irq(irq);
>> 	else
>> 		setup_polling()
>>
>> I'd change that to
>>
>> 	irq = platform_get_irq_optional(...)
>> 	if (irq > 0) /* or >= 0 ? */
>> 		setup_irq(irq)
>> 	else if (irq == -ENXIO)
>> 		setup_polling()
>> 	else
>> 		return irq
>>
>> This still has to mention -ENXIO, but this is ok and checking for 0 just
>> hardcodes a different return value.
> 
> It's what we are against of. The idea is to have
> 
> 	irq = platform_get_irq_optional(...)
> 	if (irq < 0) // we do not care about special cookies here
> 		return irq;
> 
> 	if (irq)
> 		setup_irq(irq)
> 	else
> 		setup_polling()
> 
> See the difference? Your code is convoluted.

   ... and it's longer when you look at the translated code! :-)

[...]

MBR, Sergey