net: vertexcom: mse102x: Return code for mse102x_rx_pkt_spi

The MSE102x doesn't provide any interrupt register, so the only way
to handle the level interrupt is to fetch the whole packet from
the MSE102x internal buffer via SPI. So in cases the interrupt
handler fails to do this, it should return IRQ_NONE. This allows
the core to disable the interrupt in case the issue persists
and prevent an interrupt storm.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://patch.msgid.link/20250509120435.43646-6-wahrenst@gmx.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/vertexcom/mse102x.c b/drivers/net/ethernet/vertexcom/mse102x.c
index 01bbcb4d540b0c6fe61493dbf356c6f4b15e37a7..5abb1240ad4ca9b17a1f1fc6b4eaec0620584e58 100644 (file)
--- a/drivers/net/ethernet/vertexcom/mse102x.c
+++ b/drivers/net/ethernet/vertexcom/mse102x.c
@@ -310,7 +310,7 @@ static void mse102x_dump_packet(const char *msg, int len, const char *data)
                       data, len, true);
 }
 
-static void mse102x_rx_pkt_spi(struct mse102x_net *mse)
+static irqreturn_t mse102x_rx_pkt_spi(struct mse102x_net *mse)
 {
        struct sk_buff *skb;
        unsigned int rxalign;
@@ -331,7 +331,7 @@ static void mse102x_rx_pkt_spi(struct mse102x_net *mse)
                mse102x_tx_cmd_spi(mse, CMD_CTR);
                ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
                if (ret)
-                       return;
+                       return IRQ_NONE;
 
                cmd_resp = be16_to_cpu(rx);
                if ((cmd_resp & CMD_MASK) != CMD_RTS) {
@@ -364,7 +364,7 @@ drop:
        rxalign = ALIGN(rxlen + DET_SOF_LEN + DET_DFT_LEN, 4);
        skb = netdev_alloc_skb_ip_align(mse->ndev, rxalign);
        if (!skb)
-               return;
+               return IRQ_NONE;
 
        /* 2 bytes Start of frame (before ethernet header)
         * 2 bytes Data frame tail (after ethernet frame)
@@ -374,7 +374,7 @@ drop:
        if (mse102x_rx_frame_spi(mse, rxpkt, rxlen, drop)) {
                mse->ndev->stats.rx_errors++;
                dev_kfree_skb(skb);
-               return;
+               return IRQ_HANDLED;
        }
 
        if (netif_msg_pktdata(mse))
@@ -385,6 +385,8 @@ drop:
 
        mse->ndev->stats.rx_packets++;
        mse->ndev->stats.rx_bytes += rxlen;
+
+       return IRQ_HANDLED;
 }
 
 static int mse102x_tx_pkt_spi(struct mse102x_net *mse, struct sk_buff *txb,
@@ -516,12 +518,13 @@ static irqreturn_t mse102x_irq(int irq, void *_mse)
 {
        struct mse102x_net *mse = _mse;
        struct mse102x_net_spi *mses = to_mse102x_spi(mse);
+       irqreturn_t ret;
 
        mutex_lock(&mses->lock);
-       mse102x_rx_pkt_spi(mse);
+       ret = mse102x_rx_pkt_spi(mse);
        mutex_unlock(&mses->lock);
 
-       return IRQ_HANDLED;
+       return ret;
 }
 
 static int mse102x_net_open(struct net_device *ndev)