linux-kernel - [PATCH 3/3] rtc: ds1685: disable interrupts when moving work to work queue

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Date:   Thu, 11 Apr 2019 16:33:23 +0200
From:   Thomas Bogendoerfer <tbogendoerfer@...e.de>
To:     Joshua Kinard <kumba@...too.org>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 3/3] rtc: ds1685: disable interrupts when moving work to work queue

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.

Fixes: aaaf5fbf56f1 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@...e.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