Re: [PATCH] pinctrl: samsung: use raw_spinlock for locking

From: Krzysztof Kozlowski <krzk@kernel.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Chanho Park <chanho61.park@samsung.com>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-samsung-soc <linux-samsung-soc@vger.kernel.org>
Subject: Re: [PATCH] pinctrl: samsung: use raw_spinlock for locking
Date: Fri, 22 Jan 2021 14:21:39 +0100	[thread overview]
Message-ID: <20210122132139.cowdrtjhdoicdsvv@kozik-lap> (raw)
In-Reply-To: <CACRpkdZ26sNR+oZy_f6JR4ZuNWS9PoVAm-OuNwgzCAuhEBGTeQ@mail.gmail.com>

On Fri, Jan 22, 2021 at 02:15:18PM +0100, Linus Walleij wrote:
> On Thu, Jan 21, 2021 at 4:00 AM Chanho Park <chanho61.park@samsung.com> wrote:
> 
> > This patch converts spin_[lock|unlock] functions of pin bank to
> > raw_spinlock to support preempt-rt. This can avoid BUG() assertion when
> > irqchip callbacks are triggerred. Spinlocks can be converted rt_mutex
> > which is preemptible when we apply preempt-rt patches.
> >
> > According to "Documentation/driver-api/gpio/driver.rst",
> >
> > "Realtime considerations: a realtime compliant GPIO driver should not
> > use spinlock_t or any sleepable APIs (like PM runtime) as part of its
> > irqchip implementation.
> >
> > - spinlock_t should be replaced with raw_spinlock_t.[1]
> > "
> >
> > Cc: Tomasz Figa <tomasz.figa@gmail.com>
> > Cc: Krzysztof Kozlowski <krzk@kernel.org>
> > Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> > Cc: Linus Walleij <linus.walleij@linaro.org>
> > Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> 
> Looks correct to me.
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Krzysztof, will you collect Samsung patches for this merge window or
> shall I apply it directly?

I don't have anything in the queue so far and I don't see any patches
incomming, so maybe take it directly?

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof