[PATCH 5.4 146/154] can: flexcan: only change CAN state when link up in system PM

Greg Kroah-Hartman
2025-04-08T12:08:49Z

From: Haibo Chen <haibo.chen@nxp.com>

[ Upstream commit fd99d6ed20234b83d65b9c5417794343577cf3e5 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/can/flexcan.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 7ec15cb356c01..69b4318b1a77e 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1723,8 +1723,9 @@ 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 err;
}
@@ -1735,7 +1736,6 @@ static int __maybe_unused flexcan_resume(struct device *device)
struct flexcan_priv *priv = netdev_priv(dev);
int err = 0;

- priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(dev)) {
netif_device_attach(dev);
netif_start_queue(dev);
@@ -1747,6 +1747,8 @@ static int __maybe_unused flexcan_resume(struct device *device)
} else {
err = flexcan_chip_enable(priv);
}
+
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
}

return err;
--
2.39.5