From: luojiaxing <luojiaxing@huawei.com>
To: Marc Zyngier <maz@kernel.org>, Linus Walleij <linus.walleij@linaro.org>
Cc: Serge Semin <fancer.lancer@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
"Bartosz Golaszewski" <bgolaszewski@baylibre.com>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, Linuxarm <linuxarm@huawei.com>
Subject: Re: [PATCH v1] gpio: dwapb: mask/unmask IRQ when disable/enable it
Date: Mon, 7 Dec 2020 21:10:24 +0800 [thread overview]
Message-ID: <1cc78cf1-edfb-4327-c99c-b3603dc0b3be@huawei.com> (raw)
In-Reply-To: <a18dfb3ef4dd80dddbd038507d9b8b2f@kernel.org>
On 2020/12/7 2:50, Marc Zyngier wrote:
> On 2020-12-06 15:02, Linus Walleij wrote:
>> On Sat, Dec 5, 2020 at 11:15 PM Serge Semin <fancer.lancer@gmail.com>
>> wrote:
>>
>>> Hmm, that sounds like a problem, but the explanation is a bit unclear
>>> to me. AFAICS you are saying that the only callbacks which are
>>> called during the IRQ request/release are the irq_enable(), right? If
>>> so then the only reason why we haven't got a problem reported due to
>>> that so far is that the IRQs actually unmasked by default.
>>
>> What we usually do in cases like that (and I have discussed this
>> with tglx in the past I think) is to simply mask off all IRQs in
>> probe().
>> Then they will be unmasked when requested by drivers.
>>
>> See e.g. gpio-pl061 that has this line in probe():
>> writeb(0, pl061->base + GPIOIE); /* disable irqs */
>
> This should definitely be the default behaviour. The code code
> expects all interrupt sources to be masked until actively enabled,
> usually with the IRQ being requested.
I think this patch is used for that purpose. I do two things in
irq_enable(): unmask irq and then enable IRQ;
and for irq_disable(), it's similar; mask IRQ then disable it.
Thanks
Jiaxing
>
> Thanks,
>
> M.
next prev parent reply other threads:[~2020-12-07 13:11 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 9:36 [PATCH v1] gpio: dwapb: mask/unmask IRQ when disable/enable it Luo Jiaxing
2020-11-30 11:22 ` Andy Shevchenko
2020-12-01 8:59 ` luojiaxing
2020-12-05 22:15 ` Serge Semin
2020-12-06 15:02 ` Linus Walleij
2020-12-06 18:50 ` Marc Zyngier
2020-12-07 13:10 ` luojiaxing [this message]
2021-01-06 10:24 ` Bartosz Golaszewski
[not found] ` <CAHp75VcFo2hc1kjP9jLxmCdN79rD2R4vCw2P8UssbWe2v4zwcw@mail.gmail.com>
2021-01-07 12:20 ` Serge Semin
2020-12-07 13:04 ` luojiaxing
2020-12-07 12:44 ` luojiaxing
2020-12-05 21:58 ` Linus Walleij
2023-12-15 8:09 ` Thomas Gleixner
2023-12-15 10:24 ` Serge Semin
2023-12-15 10:56 ` Thomas Gleixner
2023-12-15 12:57 ` Serge Semin
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