can: flexcan: only change CAN state when link up in system PM

After a suspend/resume cycle on a down interface, it will come up as
ERROR-ACTIVE.

$ ip -details -s -s a s dev flexcan0
3: flexcan0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN group default qlen 10
    link/can  promiscuity 0 allmulti 0 minmtu 0 maxmtu 0
    can state STOPPED (berr-counter tx 0 rx 0) restart-ms 1000

$ sudo systemctl suspend

$ ip -details -s -s a s dev flexcan0
3: flexcan0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN group default qlen 10
    link/can  promiscuity 0 allmulti 0 minmtu 0 maxmtu 0
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 1000

And only set CAN state to CAN_STATE_ERROR_ACTIVE when resume process
has no issue, otherwise keep in CAN_STATE_SLEEPING as suspend did.

Fixes: 4de349e786a3 ("can: flexcan: fix resume function")
Cc: stable@vger.kernel.org
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20250314110145.899179-1-haibo.chen@nxp.com
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Closes: https://lore.kernel.org/all/20250314-married-polar-elephant-b15594-mkl@pengutronix.de
[mkl: add newlines]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index ac1a860986df69a1dd64c25ff879490d5b21073b..3a71fd2357222f4cdcf230102829d117faf5a486 100644 (file)
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -2266,8 +2266,9 @@ static int __maybe_unused flexcan_suspend(struct device *device)
                }
                netif_stop_queue(dev);
                netif_device_detach(dev);
+
+               priv->can.state = CAN_STATE_SLEEPING;
        }
-       priv->can.state = CAN_STATE_SLEEPING;
 
        return 0;
 }
@@ -2278,7 +2279,6 @@ static int __maybe_unused flexcan_resume(struct device *device)
        struct flexcan_priv *priv = netdev_priv(dev);
        int err;
 
-       priv->can.state = CAN_STATE_ERROR_ACTIVE;
        if (netif_running(dev)) {
                netif_device_attach(dev);
                netif_start_queue(dev);
@@ -2298,6 +2298,8 @@ static int __maybe_unused flexcan_resume(struct device *device)
 
                        flexcan_chip_interrupts_enable(dev);
                }
+
+               priv->can.state = CAN_STATE_ERROR_ACTIVE;
        }
 
        return 0;