ARM: mxs: warnings on PM resume

On Sun, Jun 12, 2016 at 11:45:50PM +0200, Stefan Wahren wrote:

Hi,

quoted

Russell King - ARM Linux [off-list ref] hat am 12. Juni 2016 um 15:54
geschrieben:

This isn't about the state of the interrupt controller.  It's about
the state of the IRQ mask bit in the CPUs CPSR.

irq_disabled() returns true when the I bit in CPSR is set, false
otherwise.

What it's pointing towards is some driver being unreasonable, and
clearing the CPUs CPSR I bit after the core PM code has set it.  Causes
can be using spin_lock_irq()/spin_unlock_irq()/local_irq_enable() etc
inappropriately, rather than using the irqsave/irqrestore versions.

i finally found the reason for the warning: clk_get_sys was called inside of
mxs_suspend_enter.
After moving it into the init function the issue disappear.

Hmm.  I suspect a faster way to have found that issue would be to build
your development kernels with more debugging options enabled - eg,
check that you have DEBUG_ATOMIC_SLEEP enabled.

That should have caught the attempt to take a mutex in an IRQs-disabled
region.

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