linux-kernel - Re: [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface

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Date:   Wed, 4 Jan 2017 15:22:18 +0100
From:   David Gstir <david@...ma-star.at>
To:     Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>,
        linux-kernel@...r.kernel.org, tglx@...utronix.de,
        Richard Weinberger <richard@....at>, stable@...r.kernel.org,
        Andres Salomon <dilinger@...ued.net>
Subject: Re: [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface

Hi Daniel,

> On 04.01.2017, at 15:19, Daniel Lezcano <daniel.lezcano@...aro.org> wrote:
> 
> On 02/01/2017 10:34, Viresh Kumar wrote:
> 
> [ ... ]
> 
>>> --- a/drivers/clocksource/cs5535-clockevt.c
>>> +++ b/drivers/clocksource/cs5535-clockevt.c
>>> @@ -117,7 +117,8 @@ static irqreturn_t mfgpt_tick(int irq, void *dev_id)
>>> 	/* Turn off the clock (and clear the event) */
>>> 	disable_timer(cs5535_event_clock);
>>> 
>>> -	if (clockevent_state_shutdown(&cs5535_clockevent))
>>> +	if (clockevent_state_shutdown(&cs5535_clockevent) ||
>>> +			clockevent_state_detached(&cs5535_clockevent))
>>> 		return IRQ_HANDLED;
>>> 
>>> 	/* Clear the counter */
>> 
>> Sorry for breaking it, but it looks we have unearthed a bug because of
>> my patch.
>> 
>> I wouldn't enable the IRQ unless the clockevents core has asked for
>> it, i.e. by calling set_state_periodic() or set_state_oneshot().
>> 
>> The driver is currently enabling the IRQ from its init code and that's
>> where the problem is IMHO.
> 
> Hi David,
> 
> can you look at this ?

Yes, sure! I’ll get back to you with a new patch.

- David