[PATCH v2 07/12] can: ifi_canfd: fix {rx,tx}_errors statistics

[Dario Binacchi <dario.binacchi@amarulasolutions.com>]

The ifi_canfd_handle_lec_err() function was incorrectly incrementing only
the receive error counter, even in cases of bit or acknowledgment errors
that occur during transmission. The patch fixes the issue by incrementing
the appropriate counter based on the type of error.

Fixes: 5bbd655a8bd0 ("can: ifi: Add more detailed error reporting")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

Changes in v2:
- Update statistics even if skb allocation fails

 drivers/net/can/ifi_canfd/ifi_canfd.c | 58 ++++++++++++++++++---------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index d32b10900d2f..c86b57d47085 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -390,36 +390,55 @@ static int ifi_canfd_handle_lec_err(struct net_device *ndev)
 		return 0;
 
 	priv->can.can_stats.bus_error++;
-	stats->rx_errors++;
 
 	/* Propagate the error condition to the CAN stack. */
 	skb = alloc_can_err_skb(ndev, &cf);
-	if (unlikely(!skb))
-		return 0;
 
 	/* Read the error counter register and check for new errors. */
-	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+	if (likely(skb))
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 
-	if (errctr & IFI_CANFD_ERROR_CTR_OVERLOAD_FIRST)
-		cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+	if (errctr & IFI_CANFD_ERROR_CTR_OVERLOAD_FIRST) {
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_ACK_ERROR_FIRST)
-		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+	if (errctr & IFI_CANFD_ERROR_CTR_ACK_ERROR_FIRST) {
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_BIT0_ERROR_FIRST)
-		cf->data[2] |= CAN_ERR_PROT_BIT0;
+	if (errctr & IFI_CANFD_ERROR_CTR_BIT0_ERROR_FIRST) {
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT0;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_BIT1_ERROR_FIRST)
-		cf->data[2] |= CAN_ERR_PROT_BIT1;
+	if (errctr & IFI_CANFD_ERROR_CTR_BIT1_ERROR_FIRST) {
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT1;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_STUFF_ERROR_FIRST)
-		cf->data[2] |= CAN_ERR_PROT_STUFF;
+	if (errctr & IFI_CANFD_ERROR_CTR_STUFF_ERROR_FIRST) {
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_CRC_ERROR_FIRST)
-		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+	if (errctr & IFI_CANFD_ERROR_CTR_CRC_ERROR_FIRST) {
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+	}
 
-	if (errctr & IFI_CANFD_ERROR_CTR_FORM_ERROR_FIRST)
-		cf->data[2] |= CAN_ERR_PROT_FORM;
+	if (errctr & IFI_CANFD_ERROR_CTR_FORM_ERROR_FIRST) {
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_FORM;
+	}
 
 	/* Reset the error counter, ack the IRQ and re-enable the counter. */
 	writel(IFI_CANFD_ERROR_CTR_ER_RESET, priv->base + IFI_CANFD_ERROR_CTR);
@@ -427,6 +446,9 @@ static int ifi_canfd_handle_lec_err(struct net_device *ndev)
 	       priv->base + IFI_CANFD_INTERRUPT);
 	writel(IFI_CANFD_ERROR_CTR_ER_ENABLE, priv->base + IFI_CANFD_ERROR_CTR);
 
+	if (unlikely(!skb))
+		return 0;
+
 	netif_receive_skb(skb);
 
 	return 1;
-- 
2.43.0