[PATCH v2] can: rcar_can: Fix suspend/resume

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

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")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Ayumi Nakamichi <ayumi.nakamichi.kf@renesas.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Tested-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 Changes from v1:
 - Add Reviewed-by and Tested-by.
 - Remove unrelated modification.
 https://lore.kernel.org/all/20210921051959.50309-1-yoshihiro.shimoda.uh@renesas.com/

 drivers/net/can/rcar/rcar_can.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c
index 00e4533c8bdd..8999ec9455ec 100644
--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -846,10 +846,12 @@ static int __maybe_unused rcar_can_suspend(struct device *dev)
 	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);
@@ -868,6 +870,9 @@ static int __maybe_unused rcar_can_resume(struct device *dev)
 	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);
@@ -881,10 +886,9 @@ static int __maybe_unused rcar_can_resume(struct device *dev)
 	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;
 }
 
-- 
2.25.1