Re: [PATCH 3/3] rtc: ds1685: disable interrupts when moving work to work queue

Alexandre Belloni
2019-04-12T10:14:23Z

On 11/04/2019 16:33:23+0200, Thomas Bogendoerfer wrote:
> Handling of extended interrupts (kickstart, wake-up, ram-clear) is
> moved off to a work queue, but the interrupts aren't acknowledged
> in the interrupt handler. This leads to a deadlock, if driver
> is used with interrupts. To fix this we now disable in irq handler
> and re-enable it after work queue is done.
>

The correct fix to that seems to switch to a threaded interrupt handler.
Can you do that?

> Fixes: aaaf5fbf56f1 ("rtc: add driver for DS1685 family of real time clocks")
> Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
> ---
> drivers/rtc/rtc-ds1685.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c
> index 929f28375b87..5dabfa57bd2a 100644
> --- a/drivers/rtc/rtc-ds1685.c
> +++ b/drivers/rtc/rtc-ds1685.c
> @@ -635,6 +635,7 @@ ds1685_rtc_irq_handler(int irq, void *dev_id)
> * to be minimized. Schedule them into a workqueue
> * and inform the RTC core that the IRQs were handled.
> */
> + disable_irq_nosync(rtc->irq_num);
> spin_unlock(&rtc->lock);
> schedule_work(&rtc->work);
> rtc_update_irq(rtc->dev, 0, 0);
> @@ -741,6 +742,7 @@ ds1685_rtc_work_queue(struct work_struct *work)
> ds1685_rtc_switch_to_bank0(rtc);
>
> mutex_unlock(rtc_mutex);
> + enable_irq(rtc->irq_num);
> }
> /* ----------------------------------------------------------------------- */
>
> --
> 2.13.7
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering