can: rcar_can: rcar_can_resume(): fix s2ram with PSCI

[ Upstream commit 5c793afa07da6d2d4595f6c73a2a543a471bb055 ]

On R-Car Gen3 using PSCI, s2ram powers down the SoC.  After resume, the
CAN interface no longer works, until it is brought down and up again.

Fix this by calling rcar_can_start() from the PM resume callback, to
fully initialize the controller instead of just restarting it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/699b2f7fcb60b31b6f976a37f08ce99c5ffccb31.1755165227.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c
index 134eda66f0dcf7098aaa60f51dfc106ba55f3747..e759d940977a80b89a046f39c9a726ada485fbdb 100644 (file)
--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -867,7 +867,6 @@ static int __maybe_unused rcar_can_resume(struct device *dev)
 {
        struct net_device *ndev = dev_get_drvdata(dev);
        struct rcar_can_priv *priv = netdev_priv(ndev);
-       u16 ctlr;
        int err;
 
        if (!netif_running(ndev))
@@ -879,12 +878,7 @@ static int __maybe_unused rcar_can_resume(struct device *dev)
                return err;
        }
 
-       ctlr = readw(&priv->regs->ctlr);
-       ctlr &= ~RCAR_CAN_CTLR_SLPM;
-       writew(ctlr, &priv->regs->ctlr);
-       ctlr &= ~RCAR_CAN_CTLR_CANM;
-       writew(ctlr, &priv->regs->ctlr);
-       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+       rcar_can_start(ndev);
 
        netif_device_attach(ndev);
        netif_start_queue(ndev);