RE: [PATCH v3 1/1] input: add support for Nomadik SKE keypad controller

[Sundar R IYER <sundar.iyer@stericsson.com>]

Hi Dmitry,

>-----Original Message-----
>From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
>>
>> +static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
>> (...)
>> +       /*
>> +        * if KPASON is not ready, we cannot read data registers
>> +        * so wait for a debounce period; if still not settled,
>> +        * we fire a timer and exit the IRQ
>> +        */
>> +       while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && timeout--)
>> +               cpu_relax();
>>
>> Active polling. Surely you want this to be preemptible? Thus ->
>> threaded handler.
>>
>
>Actually I'd like that form of active polling not be there at all.
>

Hmm. Could you please help me out on how I can proceed with the 
following two HW constraints:

1. KPASON polling needs to be waited in case of a multi key press so that
the keypad registers can stabilize. This is what the TRM states.

2. If I move enabling the interrupts to the timer snippet, I end up breaking multi-key
detection.

Regards,
Sundar