* [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface
@ 2016-12-28 21:56 David Gstir
2017-01-02 9:34 ` Viresh Kumar
0 siblings, 1 reply; 3+ messages in thread
From: David Gstir @ 2016-12-28 21:56 UTC (permalink / raw)
To: linux-kernel
Cc: daniel.lezcano, tglx, richard, stable, Andres Salomon, Viresh Kumar
Since migrating to the 'set-state' interface the cs5535 driver causes a
crash after loading: Right after initialization, the IRQ handler
(mfgpt_tick) is triggered with clock event device in detached state. This
state not properly handled and causes a crash through NULL pointer
dereference upon calling the clockevent's event_handler.
This patch fixes this by handling the detached state the same way the
shutdown state is handled.
Fixes: 8f9327cbb6e8 ("clockevents/drivers/cs5535: Migrate to new 'set-state' interface")
Cc: stable@vger.kernel.org
Cc: Andres Salomon <dilinger@queued.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: David Gstir <david@sigma-star.at>
---
drivers/clocksource/cs5535-clockevt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
index 9a7e37cf56b0..649e0cd90805 100644
--- 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 */
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface
2016-12-28 21:56 [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface David Gstir
@ 2017-01-02 9:34 ` Viresh Kumar
[not found] ` <0d828ca5-4bc1-213b-f8ce-d4cfbbe9e619@linaro.org>
0 siblings, 1 reply; 3+ messages in thread
From: Viresh Kumar @ 2017-01-02 9:34 UTC (permalink / raw)
To: David Gstir
Cc: linux-kernel, daniel.lezcano, tglx, richard, stable, Andres Salomon
On 28-12-16, 22:56, David Gstir wrote:
> Since migrating to the 'set-state' interface the cs5535 driver causes a
> crash after loading: Right after initialization, the IRQ handler
> (mfgpt_tick) is triggered with clock event device in detached state. This
> state not properly handled and causes a crash through NULL pointer
> dereference upon calling the clockevent's event_handler.
>
> This patch fixes this by handling the detached state the same way the
> shutdown state is handled.
>
> Fixes: 8f9327cbb6e8 ("clockevents/drivers/cs5535: Migrate to new 'set-state' interface")
> Cc: stable@vger.kernel.org
> Cc: Andres Salomon <dilinger@queued.net>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: David Gstir <david@sigma-star.at>
> ---
> drivers/clocksource/cs5535-clockevt.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
> index 9a7e37cf56b0..649e0cd90805 100644
> --- 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.
--
viresh
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface
[not found] ` <0d828ca5-4bc1-213b-f8ce-d4cfbbe9e619@linaro.org>
@ 2017-01-04 14:22 ` David Gstir
0 siblings, 0 replies; 3+ messages in thread
From: David Gstir @ 2017-01-04 14:22 UTC (permalink / raw)
To: Daniel Lezcano
Cc: Viresh Kumar, linux-kernel, tglx, Richard Weinberger, stable,
Andres Salomon
Hi Daniel,
> On 04.01.2017, at 15:19, Daniel Lezcano <daniel.lezcano@linaro.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
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-01-04 14:23 UTC | newest]
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2016-12-28 21:56 [PATCH] clockevents/drivers/cs5535: Un-break driver with 'set-state' interface David Gstir
2017-01-02 9:34 ` Viresh Kumar
[not found] ` <0d828ca5-4bc1-213b-f8ce-d4cfbbe9e619@linaro.org>
2017-01-04 14:22 ` David Gstir
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