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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Ayumi Nakamichi <ayumi.nakamichi.kf@renesas.com>,
        Ulrich Hecht <uli+renesas@fpond.eu>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 4.19 12/37] can: rcar_can: fix suspend/resume
Date:   Mon, 25 Oct 2021 21:14:37 +0200
Message-Id: <20211025190930.658769124@linuxfoundation.org>
In-Reply-To: <20211025190926.680827862@linuxfoundation.org>
References: <20211025190926.680827862@linuxfoundation.org>
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From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

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@renesas.com
Cc: stable@vger.kernel.org
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>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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;
 }