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