Re: [RFC,PATCH 1/2] Add a common struct clk

[Uwe Kleine-König]

On Fri, Jun 11, 2010 at 11:23:56AM +0200, Lothar Waßmann wrote:
> Hi,
> 
> > > Using a mutex in clk_enable()/clk_disable() is a bad idea, since that
> > > makes it impossible to call those functions in interrupt context.
IMHO if a device generates an irq its clock should already be on.  This
way you don't need to enable or disable a clock in irq context.
 
> > Do we do this at the moment? I know at least one implementation of clk_enable 
> > uses a mutex for locking.
> > 
> You are probably talking about the Freescale i.MX51 kernel, that won't
> even boot, if you enable CONFIG_DEBUG_KERNEL, CONFIG_DEBUG_SPINLOCK,
> CONFIG_DEBUG_LOCKDEP and CONFIG_DEBUG_SPINLOCK_SLEEP.
> The mutex in the clock implementation is one of the reasons.
I will have a look into this later today.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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