linux-kernel - Re: [patch 1/5] pinctrl: samsung: Remove bogus irq

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Message-ID: <CA+Ln22Esc-1P6bcMeXuTVztiyFMXsOV1O0V=tZOj4YEwLZJSuQ@mail.gmail.com>
Date:   Fri, 30 Jun 2017 15:20:41 +0900
From:   Tomasz Figa <tomasz.figa@...il.com>
To:     Krzysztof Kozlowski <krzk@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Sylwester Nawrocki <s.nawrocki@...sung.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Marc Zyngier <marc.zyngier@....com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Brian Norris <briannorris@...omium.org>,
        Heiko Stuebner <heiko@...ech.de>,
        linux-rockchip@...ts.infradead.org,
        Julia Cartwright <julia@...com>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        John Keeping <john@...anate.com>,
        Doug Anderson <dianders@...omium.org>,
        Kukjin Kim <kgene@...nel.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        "linux-samsung-soc@...r.kernel.org" 
        <linux-samsung-soc@...r.kernel.org>
Subject: Re: [patch 1/5] pinctrl: samsung: Remove bogus irq_[un]mask from
 resource management

2017-06-30 15:02 GMT+09:00 Krzysztof Kozlowski <krzk@...nel.org>:
> On Fri, Jun 30, 2017 at 4:47 AM, Tomasz Figa <tomasz.figa@...il.com> wrote:
>> Hi Thomas,
>>
>> 2017-06-30 6:33 GMT+09:00 Thomas Gleixner <tglx@...utronix.de>:
>>> The irq chip callbacks irq_request/release_resources() have absolutely no
>>> business with masking and unmasking the irq.
>>>
>>> The core code unmasks the interrupt after complete setup and masks it
>>> before invoking irq_release_resources().
>>>
>>> The unmask is actually harmful as it happens before the interrupt is
>>> completely initialized in __setup_irq().
>>>
>>> Remove it.
>>
>> Good catch, thanks! (Note that the original patch of mine [1] did that
>> in .irq_startup()/.irq_shutdown(), which was for some reason changed
>> later, but I don't remember the exact story.)
>>
>> [1] https://patchwork.kernel.org/patch/4466431/
>>
>> Acked-by: Tomasz Figa <tomasz.figa@...il.com>
>>
>> Sylwester, Krzysztof, would you be able to do some basic test?
>
> I suppose this was not tested so yes - I have platforms do this. I
> understand that checking any non-shared GPIO interrupt should be
> sufficient to test, right?

I think any interrupt from the Exynos pin controller should work, even
shared one. I'd expect irq_request_resources() to be invoked for
shared interrupts as well, otherwise we have a problem... (I quickly
looked through kernel/irq/manage.c and it seems to be invoked for the
first __setup_irq() call even for shared interrupts.)

Thanks.

Best regards,
Tomasz