[PATCH 4.19 12/37] can: rcar_can: fix suspend/resume

[Greg Kroah-Hartman]

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>

commit f7c05c3987dcfde9a4e8c2d533db013fabebca0d upstream.

If the driver was not opened, rcar_can_suspend() should not call
clk_disable() because the clock was not enabled.

Fixes: fd1159318e55 ("can: add Renesas R-Car CAN driver")
Link: https://lore.kernel.org/all/20210924075556.223685-1-yoshihiro.shimoda.uh@xxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Tested-by: Ayumi Nakamichi <ayumi.nakamichi.kf@xxxxxxxxxxx>
Reviewed-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
Tested-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/can/rcar/rcar_can.c |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -857,10 +857,12 @@ static int __maybe_unused rcar_can_suspe
 	struct rcar_can_priv *priv = netdev_priv(ndev);
 	u16 ctlr;
 
-	if (netif_running(ndev)) {
-		netif_stop_queue(ndev);
-		netif_device_detach(ndev);
-	}
+	if (!netif_running(ndev))
+		return 0;
+
+	netif_stop_queue(ndev);
+	netif_device_detach(ndev);
+
 	ctlr = readw(&priv->regs->ctlr);
 	ctlr |= RCAR_CAN_CTLR_CANM_HALT;
 	writew(ctlr, &priv->regs->ctlr);
@@ -879,6 +881,9 @@ static int __maybe_unused rcar_can_resum
 	u16 ctlr;
 	int err;
 
+	if (!netif_running(ndev))
+		return 0;
+
 	err = clk_enable(priv->clk);
 	if (err) {
 		netdev_err(ndev, "clk_enable() failed, error %d\n", err);
@@ -892,10 +897,9 @@ static int __maybe_unused rcar_can_resum
 	writew(ctlr, &priv->regs->ctlr);
 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
-	if (netif_running(ndev)) {
-		netif_device_attach(ndev);
-		netif_start_queue(ndev);
-	}
+	netif_device_attach(ndev);
+	netif_start_queue(ndev);
+
 	return 0;
 }