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: 4de349e ("can: flexcan: fix resume function")
Cc: [email protected]
Signed-off-by: Haibo Chen <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reported-by: Marc Kleine-Budde <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]
[mkl: add newlines]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: Haibo Chen

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;