From: alexandre.belloni@free-electrons.com (Alexandre Belloni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv8 1/2] pwm: Add Allwinner SoC support
Date: Mon, 20 Oct 2014 12:29:39 +0200 [thread overview]
Message-ID: <20141020102939.GB10616@piout.net> (raw)
In-Reply-To: <54442BB1.1080403@mleia.com>
Hi,
On 20/10/2014 at 00:22:57 +0300, Vladimir Zapolskiy wrote :
> > +struct sun4i_pwm_chip {
> > + struct pwm_chip chip;
> > + struct clk *clk;
> > + void __iomem *base;
> > + struct mutex ctrl_lock;
>
> why do you use mutex? I haven't found any blocking subcalls under
> protection, a spinlock seems to fit better here.
>
A mutex here will do the right thing. The lock is never taken in
interrupt context and a mutex is spinning for a few cycles before
putting the thread to sleep. I'm not sure why you feel a spinlock would
be better here.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2014-10-20 10:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-19 18:28 [PATCHv8 0/2] Add Allwinner SoCs PWM support Alexandre Belloni
2014-10-19 18:28 ` [PATCHv8 1/2] pwm: Add Allwinner SoC support Alexandre Belloni
2014-10-19 21:22 ` Vladimir Zapolskiy
2014-10-20 10:29 ` Alexandre Belloni [this message]
2014-10-20 13:10 ` Vladimir Zapolskiy
2014-10-20 17:06 ` Alexandre Belloni
2014-10-20 17:36 ` Russell King - ARM Linux
2014-10-20 17:44 ` Vladimir Zapolskiy
2014-10-19 18:28 ` [PATCHv8 2/2] pwm: sunxi: document OF bindings Alexandre Belloni
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