* Re: [PATCH] clocksource:fix kernel panic due missing event_handler in cs5535
[not found] <1464604292-11276-1-git-send-email-ulli.kroll@googlemail.com>
@ 2016-05-30 10:35 ` Thomas Gleixner
2016-05-31 7:09 ` Hans Ulli Kroll
0 siblings, 1 reply; 2+ messages in thread
From: Thomas Gleixner @ 2016-05-30 10:35 UTC (permalink / raw)
To: Hans Ulli Kroll; +Cc: linux-kernel, Daniel Lezcano, stable
On Mon, 30 May 2016, Hans Ulli Kroll wrote:
> Missing event_handler in mfgpt_tick() caused a kernel panic.
So the real problem is that the interrupt in the device is enabled _BEFORE_
the clock event device is registered.
> diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
> index 9a7e37c..6f186cf 100644
> --- a/drivers/clocksource/cs5535-clockevt.c
> +++ b/drivers/clocksource/cs5535-clockevt.c
> @@ -129,7 +129,9 @@ static irqreturn_t mfgpt_tick(int irq, void *dev_id)
> cs5535_mfgpt_write(cs5535_event_clock, MFGPT_REG_SETUP,
> MFGPT_SETUP_CNTEN | MFGPT_SETUP_CMP2);
>
> - cs5535_clockevent.event_handler(&cs5535_clockevent);
> + if (cs5535_clockevent.event_handler)
> + cs5535_clockevent.event_handler(&cs5535_clockevent);
> +
So what about fixing the above problem instead of having a conditional in the
interrupt handler fast path?
Thanks,
tglx
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] clocksource:fix kernel panic due missing event_handler in cs5535
2016-05-30 10:35 ` [PATCH] clocksource:fix kernel panic due missing event_handler in cs5535 Thomas Gleixner
@ 2016-05-31 7:09 ` Hans Ulli Kroll
0 siblings, 0 replies; 2+ messages in thread
From: Hans Ulli Kroll @ 2016-05-31 7:09 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Hans Ulli Kroll, linux-kernel, Daniel Lezcano, stable
HI
On Mon, 30 May 2016, Thomas Gleixner wrote:
> On Mon, 30 May 2016, Hans Ulli Kroll wrote:
>
> > Missing event_handler in mfgpt_tick() caused a kernel panic.
>
> So the real problem is that the interrupt in the device is enabled _BEFORE_
> the clock event device is registered.
>
> > diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
> > index 9a7e37c..6f186cf 100644
> > --- a/drivers/clocksource/cs5535-clockevt.c
> > +++ b/drivers/clocksource/cs5535-clockevt.c
> > @@ -129,7 +129,9 @@ static irqreturn_t mfgpt_tick(int irq, void *dev_id)
> > cs5535_mfgpt_write(cs5535_event_clock, MFGPT_REG_SETUP,
> > MFGPT_SETUP_CNTEN | MFGPT_SETUP_CMP2);
> >
> > - cs5535_clockevent.event_handler(&cs5535_clockevent);
> > + if (cs5535_clockevent.event_handler)
> > + cs5535_clockevent.event_handler(&cs5535_clockevent);
> > +
>
> So what about fixing the above problem instead of having a conditional in the
> interrupt handler fast path?
>
So there in an default handler for this in the clockevent framework.
OK, for this approach.
I'll send another patch.
Greetings from Cologne
Hans Ulli Kroll
^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-05-30 10:35 ` [PATCH] clocksource:fix kernel panic due missing event_handler in cs5535 Thomas Gleixner
2016-05-31 7:09 ` Hans Ulli Kroll
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