Merge tag 'linux-can-next-for-6.7-20231005' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2023-10-05

The first patch is by Miquel Raynal and fixes a comment in the sja1000
driver.

Vincent Mailhol contributes 2 patches that fix W=1 compiler warnings
in the etas_es58x driver.

Jiapeng Chong's patch removes an unneeded NULL pointer check before
dev_put() in the CAN raw protocol.

A patch by Justin Stittreplaces a strncpy() by strscpy() in the
peak_pci sja1000 driver.

The next 5 patches are by me and fix the can_restart() handler and
replace BUG_ON()s in the CAN dev helpers with proper error handling.

The last 27 patches are also by me and target the at91_can driver.
First a new helper function is introduced, the at91_can driver is
cleaned up and updated to use the rx-offload helper.

* tag 'linux-can-next-for-6.7-20231005' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next: (37 commits)
  can: at91_can: switch to rx-offload implementation
  can: at91_can: at91_alloc_can_err_skb() introduce new function
  can: at91_can: at91_irq_err_line(): send error counters with state change
  can: at91_can: at91_irq_err_line(): make use of can_change_state() and can_bus_off()
  can: at91_can: at91_irq_err_line(): take reg_sr into account for bus off
  can: at91_can: at91_irq_err_line(): make use of can_state_get_by_berr_counter()
  can: at91_can: at91_irq_err(): rename to at91_irq_err_line()
  can: at91_can: at91_irq_err_frame(): move next to at91_irq_err()
  can: at91_can: at91_irq_err_frame(): call directly from IRQ handler
  can: at91_can: at91_poll_err(): increase stats even if no quota left or OOM
  can: at91_can: at91_poll_err(): fold in at91_poll_err_frame()
  can: at91_can: add CAN transceiver support
  can: at91_can: at91_open(): forward request_irq()'s return value in case or an error
  can: at91_can: at91_chip_start(): don't disable IRQs twice
  can: at91_can: at91_set_bittiming(): demote register output to debug level
  can: at91_can: rename struct at91_priv::{tx_next,tx_echo} to {tx_head,tx_tail}
  can: at91_can: at91_setup_mailboxes(): update comments
  can: at91_can: add more register definitions
  can: at91_can: MCR Register: convert to FIELD_PREP()
  can: at91_can: MSR Register: convert to FIELD_PREP()
  ...
====================

Link: https://lore.kernel.org/r/20231005195812.549776-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 36 insertions, 15 deletions

diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 7f9334a8af50..3a3be5cdfc1f 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -90,6 +90,28 @@ const char *can_get_state_str(const enum can_state state)
 }
 EXPORT_SYMBOL_GPL(can_get_state_str);
 
+static enum can_state can_state_err_to_state(u16 err)
+{
+	if (err < CAN_ERROR_WARNING_THRESHOLD)
+		return CAN_STATE_ERROR_ACTIVE;
+	if (err < CAN_ERROR_PASSIVE_THRESHOLD)
+		return CAN_STATE_ERROR_WARNING;
+	if (err < CAN_BUS_OFF_THRESHOLD)
+		return CAN_STATE_ERROR_PASSIVE;
+
+	return CAN_STATE_BUS_OFF;
+}
+
+void can_state_get_by_berr_counter(const struct net_device *dev,
+				   const struct can_berr_counter *bec,
+				   enum can_state *tx_state,
+				   enum can_state *rx_state)
+{
+	*tx_state = can_state_err_to_state(bec->txerr);
+	*rx_state = can_state_err_to_state(bec->rxerr);
+}
+EXPORT_SYMBOL_GPL(can_state_get_by_berr_counter);
+
 void can_change_state(struct net_device *dev, struct can_frame *cf,
 		      enum can_state tx_state, enum can_state rx_state)
 {
@@ -132,7 +154,8 @@ static void can_restart(struct net_device *dev)
 	struct can_frame *cf;
 	int err;
 
-	BUG_ON(netif_carrier_ok(dev));
+	if (netif_carrier_ok(dev))
+		netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n");
 
 	/* No synchronization needed because the device is bus-off and
 	 * no messages can come in or go out.
@@ -141,23 +164,21 @@ static void can_restart(struct net_device *dev)
 
 	/* send restart message upstream */
 	skb = alloc_can_err_skb(dev, &cf);
-	if (!skb)
-		goto restart;
-
-	cf->can_id |= CAN_ERR_RESTARTED;
-
-	netif_rx(skb);
-
-restart:
-	netdev_dbg(dev, "restarted\n");
-	priv->can_stats.restarts++;
+	if (skb) {
+		cf->can_id |= CAN_ERR_RESTARTED;
+		netif_rx(skb);
+	}
 
 	/* Now restart the device */
-	err = priv->do_set_mode(dev, CAN_MODE_START);
-
 	netif_carrier_on(dev);
-	if (err)
-		netdev_err(dev, "Error %d during restart", err);
+	err = priv->do_set_mode(dev, CAN_MODE_START);
+	if (err) {
+		netdev_err(dev, "Restart failed, error %pe\n", ERR_PTR(err));
+		netif_carrier_off(dev);
+	} else {
+		netdev_dbg(dev, "Restarted\n");
+		priv->can_stats.restarts++;
+	}
 }
 
 static void can_restart_work(struct work_struct *work)