On 03/19/2018 10:48 AM, Sasha Levin wrote:
From: David Lechner <[email protected]>
[ Upstream commit a12aa8a68dfef5de181f2e555aa950a0ab05411f ]
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 <[email protected]>
Signed-off-by: David Lechner <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
I don't know of any existing bugs in v4.15 that this fixes, so I don't
think this really fits the criteria for stable.
