Merge tag 'linux-can-next-for-6.7-20231005' of...

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.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/can/Kconfig

@@ -89,6 +89,7 @@ config CAN_RX_OFFLOAD
 config CAN_AT91
 	tristate "Atmel AT91 onchip CAN controller"
 	depends on (ARCH_AT91 || COMPILE_TEST) && HAS_IOMEM
+	select CAN_RX_OFFLOAD
 	help
 	  This is a driver for the SoC CAN controller in Atmel's AT91SAM9263
 	  and AT91SAM9X5 processors.

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)

drivers/net/can/dev/skb.c

@@ -49,7 +49,11 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 {
 	struct can_priv *priv = netdev_priv(dev);
 
-	BUG_ON(idx >= priv->echo_skb_max);
+	if (idx >= priv->echo_skb_max) {
+		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
+			   __func__, idx, priv->echo_skb_max);
+		return -EINVAL;
+	}
 
 	/* check flag whether this packet has to be looped back */
 	if (!(dev->flags & IFF_ECHO) ||

drivers/net/can/sja1000/peak_pci.c

@@ -462,7 +462,7 @@ static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
 		card->led_chip.owner = THIS_MODULE;
 		card->led_chip.dev.parent = &pdev->dev;
 		card->led_chip.algo_data = &card->i2c_bit;
-		strncpy(card->led_chip.name, "peak_i2c",
+		strscpy(card->led_chip.name, "peak_i2c",
 			sizeof(card->led_chip.name));
 
 		card->i2c_bit = peak_pciec_i2c_bit_ops;

drivers/net/can/sja1000/sja1000.c

@@ -206,7 +206,7 @@ static void sja1000_start(struct net_device *dev)
 {
 	struct sja1000_priv *priv = netdev_priv(dev);
 
-	/* leave reset mode */
+	/* enter reset mode */
 	if (priv->can.state != CAN_STATE_STOPPED)
 		set_reset_mode(dev);
 

drivers/net/can/usb/etas_es58x/es58x_core.c

@@ -2230,6 +2230,7 @@ static int es58x_probe(struct usb_interface *intf,
 
 	for (ch_idx = 0; ch_idx < es58x_dev->num_can_ch; ch_idx++) {
 		int ret = es58x_init_netdev(es58x_dev, ch_idx);
+
 		if (ret) {
 			es58x_free_netdevs(es58x_dev);
 			return ret;

drivers/net/can/usb/etas_es58x/es58x_core.h

@@ -378,13 +378,13 @@ struct es58x_sw_version {
 
 /**
  * struct es58x_hw_revision - Hardware revision number.
- * @letter: Revision letter.
+ * @letter: Revision letter, an alphanumeric character.
  * @major: Version major number, represented on three digits.
  * @minor: Version minor number, represented on three digits.
  *
  * The hardware revision uses its own format: "axxx/xxx" where 'a' is
- * a letter and 'x' a digit. It can be retrieved from the product
- * information string.
+ * an alphanumeric character and 'x' a digit. It can be retrieved from
+ * the product information string.
  */
 struct es58x_hw_revision {
 	char letter;

drivers/net/can/usb/etas_es58x/es58x_devlink.c

@@ -125,14 +125,28 @@ static int es58x_parse_hw_rev(struct es58x_device *es58x_dev,
  * firmware version, the bootloader version and the hardware
  * revision.
  *
- * If the function fails, simply emit a log message and continue
- * because product information is not critical for the driver to
- * operate.
+ * If the function fails, set the version or revision to an invalid
+ * value and emit an informal message. Continue probing because the
+ * product information is not critical for the driver to operate.
  */
 void es58x_parse_product_info(struct es58x_device *es58x_dev)
 {
+	static const struct es58x_sw_version sw_version_not_set = {
+		.major = -1,
+		.minor = -1,
+		.revision = -1,
+	};
+	static const struct es58x_hw_revision hw_revision_not_set = {
+		.letter = '\0',
+		.major = -1,
+		.minor = -1,
+	};
 	char *prod_info;
 
+	es58x_dev->firmware_version = sw_version_not_set;
+	es58x_dev->bootloader_version = sw_version_not_set;
+	es58x_dev->hardware_revision = hw_revision_not_set;
+
 	prod_info = usb_cache_string(es58x_dev->udev, ES58X_PROD_INFO_IDX);
 	if (!prod_info) {
 		dev_warn(es58x_dev->dev,
@@ -150,29 +164,36 @@ void es58x_parse_product_info(struct es58x_device *es58x_dev)
 }
 
 /**
- * es58x_sw_version_is_set() - Check if the version is a valid number.
+ * es58x_sw_version_is_valid() - Check if the version is a valid number.
  * @sw_ver: Version number of either the firmware or the bootloader.
  *
- * If &es58x_sw_version.major, &es58x_sw_version.minor and
- * &es58x_sw_version.revision are all zero, the product string could
- * not be parsed and the version number is invalid.
+ * If any of the software version sub-numbers do not fit on two
+ * digits, the version is invalid, most probably because the product
+ * string could not be parsed.
+ *
+ * Return: @true if the software version is valid, @false otherwise.
  */
-static inline bool es58x_sw_version_is_set(struct es58x_sw_version *sw_ver)
+static inline bool es58x_sw_version_is_valid(struct es58x_sw_version *sw_ver)
 {
-	return sw_ver->major || sw_ver->minor || sw_ver->revision;
+	return sw_ver->major < 100 && sw_ver->minor < 100 &&
+		sw_ver->revision < 100;
 }
 
 /**
- * es58x_hw_revision_is_set() - Check if the revision is a valid number.
+ * es58x_hw_revision_is_valid() - Check if the revision is a valid number.
  * @hw_rev: Revision number of the hardware.
  *
- * If &es58x_hw_revision.letter is the null character, the product
- * string could not be parsed and the hardware revision number is
- * invalid.
+ * If &es58x_hw_revision.letter is not a alphanumeric character or if
+ * any of the hardware revision sub-numbers do not fit on three
+ * digits, the revision is invalid, most probably because the product
+ * string could not be parsed.
+ *
+ * Return: @true if the hardware revision is valid, @false otherwise.
  */
-static inline bool es58x_hw_revision_is_set(struct es58x_hw_revision *hw_rev)
+static inline bool es58x_hw_revision_is_valid(struct es58x_hw_revision *hw_rev)
 {
-	return hw_rev->letter != '\0';
+	return isalnum(hw_rev->letter) && hw_rev->major < 1000 &&
+		hw_rev->minor < 1000;
 }
 
 /**
@@ -197,7 +218,7 @@ static int es58x_devlink_info_get(struct devlink *devlink,
 	char buf[max(sizeof("xx.xx.xx"), sizeof("axxx/xxx"))];
 	int ret = 0;
 
-	if (es58x_sw_version_is_set(fw_ver)) {
+	if (es58x_sw_version_is_valid(fw_ver)) {
 		snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
 			 fw_ver->major, fw_ver->minor, fw_ver->revision);
 		ret = devlink_info_version_running_put(req,
@@ -207,7 +228,7 @@ static int es58x_devlink_info_get(struct devlink *devlink,
 			return ret;
 	}
 
-	if (es58x_sw_version_is_set(bl_ver)) {
+	if (es58x_sw_version_is_valid(bl_ver)) {
 		snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
 			 bl_ver->major, bl_ver->minor, bl_ver->revision);
 		ret = devlink_info_version_running_put(req,
@@ -217,7 +238,7 @@ static int es58x_devlink_info_get(struct devlink *devlink,
 			return ret;
 	}
 
-	if (es58x_hw_revision_is_set(hw_rev)) {
+	if (es58x_hw_revision_is_valid(hw_rev)) {
 		snprintf(buf, sizeof(buf), "%c%03u/%03u",
 			 hw_rev->letter, hw_rev->major, hw_rev->minor);
 		ret = devlink_info_version_fixed_put(req,

include/linux/can/dev.h

@@ -195,6 +195,10 @@ int can_restart_now(struct net_device *dev);
 void can_bus_off(struct net_device *dev);
 
 const char *can_get_state_str(const enum can_state state);
+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);
 void can_change_state(struct net_device *dev, struct can_frame *cf,
 		      enum can_state tx_state, enum can_state rx_state);
 

net/can/raw.c

@@ -493,8 +493,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 
 out_put_dev:
 	/* remove potential reference from dev_get_by_index() */
-	if (dev)
-		dev_put(dev);
+	dev_put(dev);
 out:
 	release_sock(sk);
 	rtnl_unlock();