Patch "can: ifi_canfd: ifi_canfd_handle_lec_err(): fix {rx,tx}_errors statistics" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    can: ifi_canfd: ifi_canfd_handle_lec_err(): fix {rx,tx}_errors statistics

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     can-ifi_canfd-ifi_canfd_handle_lec_err-fix-rx-tx-_er.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 94a8c514f07e7beec8df7de3c7407e1d7200c712
Author: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
Date:   Fri Nov 22 23:15:48 2024 +0100

    can: ifi_canfd: ifi_canfd_handle_lec_err(): fix {rx,tx}_errors statistics
    
    [ Upstream commit bb03d568bb21b4afe7935d1943bcf68ddea3ea45 ]
    
    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.
    
    Fix 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@xxxxxxxxxxxxxxxxxxxx>
    Reviewed-by: Marek Vasut <marex@xxxxxxx>
    Link: https://patch.msgid.link/20241122221650.633981-8-dario.binacchi@xxxxxxxxxxxxxxxxxxxx
    Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 72307297d75e4..5145a6a73d2d7 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;