[PATCH 5.4 19/58] can: rcar_can: fix suspend/resume

Greg Kroah-Hartman
2021-10-25T19:35:11Z

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
@@ -848,10 +848,12 @@ 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);
@@ -870,6 +872,9 @@ 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);
@@ -883,10 +888,9 @@ 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;
}