Re: [PATCH v2] clk: fix reentrancy of clk_enable() on UP systems

From: Stephen Boyd
Date: Wed Jan 10 2018 - 16:40:50 EST


On 01/04, David Lechner wrote:
> Reentrant calls to clk_enable() are not working on UP systems. This is
> caused by the fact spin_trylock_irqsave() always returns true when
> CONFIG_SMP=n (and CONFIG_DEBUG_SPINLOCK=n) which causes the reference
> counting to not work correctly when clk_enable_lock() is called twice
> before clk_enable_unlock() is called (this happens when clk_enable()
> is called from within another clk_enable()).
>
> This fixes the problem by skipping the call to spin_trylock_irqsave() on UP
> systems and relying solely on reference counting. We also make sure to set
> flags in this case so that we are not returning an uninitialized value.
>
> Suggested-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
> ---

Applied to clk-next

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