net: vertexcom: mse102x: Fix possible stuck of SPI interrupt

[ Upstream commit 55f362885951b2d00fd7fbb02ef0227deea572c2 ]

The MSE102x doesn't provide any SPI commands for interrupt handling.
So in case the interrupt fired before the driver requests the IRQ,
the interrupt will never fire again. In order to fix this always poll
for pending packets after opening the interface.

Fixes: 2f207cb ("net: vertexcom: Add MSE102x SPI support")
Signed-off-by: Stefan Wahren <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 6abbffa736473db6da38e1ca04d5522e80bb4c2d)
Signed-off-by: Jack Vogel <[email protected]>

Author: lategoodbye

drivers/net/ethernet/vertexcom/mse102x.c

@@ -509,6 +509,7 @@ static irqreturn_t mse102x_irq(int irq, void *_mse)
 static int mse102x_net_open(struct net_device *ndev)
 {
 	struct mse102x_net *mse = netdev_priv(ndev);
+	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
 	int ret;
 
 	ret = request_threaded_irq(ndev->irq, NULL, mse102x_irq, IRQF_ONESHOT,
@@ -524,6 +525,13 @@ static int mse102x_net_open(struct net_device *ndev)
 
 	netif_carrier_on(ndev);
 
+	/* The SPI interrupt can stuck in case of pending packet(s).
+	 * So poll for possible packet(s) to re-arm the interrupt.
+	 */
+	mutex_lock(&mses->lock);
+	mse102x_rx_pkt_spi(mse);
+	mutex_unlock(&mses->lock);
+
 	netif_dbg(mse, ifup, ndev, "network device up\n");
 
 	return 0;