From: Marc Zyngier <marc.zyngier@arm.com>
To: Linus Walleij <linus.walleij@linaro.org>,
Jerome Brunet <jbrunet@baylibre.com>,
Rob Herring <robh@kernel.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>,
Bartosz Golaszewski <brgl@bgdev.pl>,
"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFT PATCH v2] gpiolib: allow gpio irqchip to map irqs dynamically
Date: Thu, 5 Oct 2017 11:59:46 +0100 [thread overview]
Message-ID: <cc95d9b3-f18d-febc-0a51-cc3846d0de85@arm.com> (raw)
In-Reply-To: <CACRpkdZAJ1c6VyHA+2P6P4GaMY51q-ANc2NLF_2o4atzz2mqrg@mail.gmail.com>
On 21/09/17 12:41, Linus Walleij wrote:
> On Fri, Sep 15, 2017 at 10:26 AM, Jerome Brunet <jbrunet@baylibre.com> wrote:
>
>> I initially planned to do some refcounting in the gpio layer but that would make
>> no sense, as you pointed out, the irq could be shared. This refcounting would
>> only make sense at the irq level.
>>
>> On a more general note, I wonder when is it safe for a driver to dispose of the
>> mapping of a possibly shared irq ? There is no way to know if the mapping is
>> still used somewhere else, or am I missing something again ?
>
> I have no idea, but maybe Marc Z or Rob H knows this?
>
> They usually have a bit of deeper IRQ-centric knowledge.
Unfortunately, there is no such thing. I contemplated tracking this at
some point, and got sidetracked. In general, the irq domain and irq core
are horribly disconnected, leading to that exact line of questioning.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2017-10-05 10:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-21 16:49 [RFT PATCH v2] gpiolib: allow gpio irqchip to map irqs dynamically Grygorii Strashko
2017-07-21 16:49 ` Grygorii Strashko
2017-08-01 7:52 ` Linus Walleij
2017-08-01 8:03 ` Jerome Brunet
2017-08-01 18:27 ` Grygorii Strashko
2017-09-15 8:26 ` Jerome Brunet
2017-09-21 11:41 ` Linus Walleij
2017-10-05 10:59 ` Marc Zyngier [this message]
2017-08-01 9:53 ` Bartosz Golaszewski
2017-09-28 8:33 ` Mika Westerberg
2017-09-28 14:02 ` Grygorii Strashko
2017-09-28 14:02 ` Grygorii Strashko
2017-09-28 14:26 ` Mika Westerberg
2017-10-08 0:27 ` Linus Walleij
2017-10-09 18:10 ` Grygorii Strashko
2017-10-09 19:57 ` Linus Walleij
2017-10-09 22:17 ` Grygorii Strashko
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