From: Jeremy Kerr <jeremy.kerr@canonical.com>
To: Lothar =?iso-8859-1?q?Wa=DFmann?= <LW@karo-electronics.de>
Subject: Re: [RFC,PATCH 1/2] Add a common struct clk
Date: Fri, 11 Jun 2010 18:50:30 +0800
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	<u.kleine-koenig@pengutronix.de>,
       linux-arm-kernel@lists.infradead.org,
       Ben Herrenchmidt <benh@kernel.crashing.org>,
       linux-kernel@vger.kernel.org, Ben Dooks <ben-linux@fluff.org>
References: <1275636608.606606.450179637764.0.gpush@pororo> <20100611095839.GC10894@pengutronix.de> <19474.2817.333749.485028@ipc1.ka-ro>
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Hi Lothar,

> You may want to disable a clock in the IRQ handler. The VPU driver in
> the Freescale BSP for i.MX51 does exactly this.

Is this something we can defer to a sleepable context?

> Anyway I don't see any reason for using a mutex here instead of
> spin_lock_irq_save() as all other implementations do.

Just that enable/disable may take an arbitrarily long time to complete. Sounds 
like that hasn't been a problem in the past though.

Cheers,


Jeremy
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