Messages in this thread |  | | Subject | Re: [PATCH AUTOSEL for 4.15 104/124] clk: fix reentrancy of clk_enable() on UP systems | From | David Lechner <> | Date | Mon, 19 Mar 2018 10:55:16 -0500 |
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On 03/19/2018 10:48 AM, Sasha Levin wrote: > From: David Lechner <david@lechnology.com> > > [ 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 <sboyd@codeaurora.org> > Signed-off-by: David Lechner <david@lechnology.com> > Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> > Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> > ---
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.
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