On R-Car Gen3 using PSCI, s2ram powers down the SoC. After resume, the
CAN-FD interface no longer works. Trying to bring it up again fails:
# ip link set can0 up
RTNETLINK answers: Connection timed out
# dmesg
...
channel 0 communication state failed
Fix this by populating the (currently empty) suspend and resume
callbacks, to stop/start the individual CAN-FD channels, and
(de)initialize the CAN-FD controller.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
While this fixes CAN-FD after resume from s2ram on R-Car E3 (Ebisu-4D),
it does introduce a regression on R-Car V4H (White Hawk): after resume
from s2idle (White Hawk does not support s2ram), CAN frames sent by
other devices are no longer received, and the other side sometimes
reports a "bus-off".
However, the underlying issue is pre-existing, and can be reproduced
without this patch: the CAN-FD controller fails in the same way after
driver unbind/rebind. So something must be missing in the
(de)initialization sequence for the R-Car Gen4 CAN-FD register layout.
Note that it keeps on working after ifdown/ifup, which does not
reinitialize the full controller.
---
drivers/net/can/rcar/rcar_canfd.c | 53 +++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index eedce83b91414c57..6b0c563e894f74b3 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -2236,11 +2236,64 @@ static void rcar_canfd_remove(struct platform_device *pdev)
static int rcar_canfd_suspend(struct device *dev)
{
+ struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
+ int err;
+ u32 ch;
+
+ for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
+ struct rcar_canfd_channel *priv = gpriv->ch[ch];
+ struct net_device *ndev = priv->ndev;
+
+ if (!netif_running(ndev))
+ continue;
+
+ netif_device_detach(ndev);
+
+ err = rcar_canfd_close(ndev);
+ if (err) {
+ netdev_err(ndev, "rcar_canfd_close() failed %pe\n",
+ ERR_PTR(err));
+ return err;
+ }
+
+ priv->can.state = CAN_STATE_SLEEPING;
+ }
+
+ /* TODO Skip if wake-up (which is not yet supported) is enabled */
+ rcar_canfd_global_deinit(gpriv, false);
+
return 0;
}
static int rcar_canfd_resume(struct device *dev)
{
+ struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
+ int err;
+ u32 ch;
+
+ err = rcar_canfd_global_init(gpriv);
+ if (err) {
+ dev_err(dev, "rcar_canfd_open() failed %pe\n", ERR_PTR(err));
+ return err;
+ }
+
+ for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
+ struct rcar_canfd_channel *priv = gpriv->ch[ch];
+ struct net_device *ndev = priv->ndev;
+
+ if (!netif_running(ndev))
+ continue;
+
+ err = rcar_canfd_open(ndev);
+ if (err) {
+ netdev_err(ndev, "rcar_canfd_open() failed %pe\n",
+ ERR_PTR(err));
+ return err;
+ }
+
+ netif_device_attach(ndev);
+ }
+
return 0;
}
--
2.43.0
