can: m_can: Start/Cancel polling timer together with interrupts

[ Upstream commit a163c5761019b94258ca655b27b46e82657fd6f5 ]

Interrupts are enabled/disabled in more places than just m_can_start()
and m_can_stop(). Couple the polling timer with enabling/disabling of
all interrupts to achieve equivalent behavior.

Cc: Judith Mendez <jm@ti.com>
Fixes: b382380 ("can: m_can: Add hrtimer to generate software interrupt")
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/all/20240207093220.2681425-2-msp@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/can/m_can/m_can.c

@@ -418,13 +418,25 @@ static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
 
 static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
 {
+	if (!cdev->net->irq) {
+		dev_dbg(cdev->dev, "Start hrtimer\n");
+		hrtimer_start(&cdev->hrtimer,
+			      ms_to_ktime(HRTIMER_POLL_INTERVAL_MS),
+			      HRTIMER_MODE_REL_PINNED);
+	}
+
 	/* Only interrupt line 0 is used in this driver */
 	m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
 }
 
 static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
 {
 	m_can_write(cdev, M_CAN_ILE, 0x0);
+
+	if (!cdev->net->irq) {
+		dev_dbg(cdev->dev, "Stop hrtimer\n");
+		hrtimer_cancel(&cdev->hrtimer);
+	}
 }
 
 /* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
@@ -1417,12 +1429,6 @@ static int m_can_start(struct net_device *dev)
 
 	m_can_enable_all_interrupts(cdev);
 
-	if (!dev->irq) {
-		dev_dbg(cdev->dev, "Start hrtimer\n");
-		hrtimer_start(&cdev->hrtimer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS),
-			      HRTIMER_MODE_REL_PINNED);
-	}
-
 	return 0;
 }
 
@@ -1577,11 +1583,6 @@ static void m_can_stop(struct net_device *dev)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
 
-	if (!dev->irq) {
-		dev_dbg(cdev->dev, "Stop hrtimer\n");
-		hrtimer_cancel(&cdev->hrtimer);
-	}
-
 	/* disable all interrupts */
 	m_can_disable_all_interrupts(cdev);