Re: [PATCH REPOST] gpio: omap: use raw locks for locking

[Javier Martinez Canillas <javier@xxxxxxxxxxxx>]

On Fri, Jun 19, 2015 at 7:42 PM, santosh shilimkar
<santosh.shilimkar@xxxxxxxxxx> wrote:
> On 6/19/2015 10:06 AM, Sebastian Andrzej Siewior wrote:
>>
>> This patch converts gpio_bank.lock from a spin_lock into a
>> raw_spin_lock. The call path is to access this lock is always under a
>> raw_spin_lock, for instance
>> - __setup_irq() holds &desc->lock with irq off
>>    + __irq_set_trigger()
>>     + omap_gpio_irq_type()
>>
>> - handle_level_irq() (runs with irqs off therefore raw locks)
>>    + mask_ack_irq()
>>     + omap_gpio_mask_irq()
>>
>> This fixes the obvious backtrace on -RT. However the locking vs context
>> is not and this is not limited to -RT:
>> - omap_gpio_irq_type() is called with IRQ off and has an conditional
>>    call to pm_runtime_get_sync() which may sleep. Either it may happen or
>>    it may not happen but pm_runtime_get_sync() should not be called with
>>    irqs off.
>>
>> - omap_gpio_debounce() is holding the lock with IRQs off.
>>    + omap2_set_gpio_debounce()
>>     + clk_prepare_enable()
>>      + clk_prepare() this one might sleep.
>>    The number of users of gpiod_set_debounce() / gpio_set_debounce()
>>    looks low but still this is not good.
>>
>> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
>> ---
>
> Should be safe to do it.
> Acked-by: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
>

Answered on the wrong thread, sorry for the noise.

Acked-by: Javier Martinez Canillas <javier@xxxxxxxxxxxx>

Best regards,
Javier
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