can: flexcan: move rx_offload_add() from flexcan_probe() to flexcan_open()

rx offload depends on number of message buffers, which in turn depends
on messgae buffer size. with the upcoming LX2160A SOC the message buffer
size can be configured to 72 bytes if it were to be used in CAN FD mode.

The current mode in which the flexcan is being operated is known at the
time of flexcan_open() but not at the time of flexcan_probe().

Therefore, move the rx_offload_add() from flexcan_probe() to
flexcan_open(). correspondingly, move rx_offload_delete() from
flexcan_remove() to flexcan_close().
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/flexcan.c

@@ -1188,6 +1188,7 @@ static void flexcan_chip_stop(struct net_device *dev)
 static int flexcan_open(struct net_device *dev)
 {
 	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->regs;
 	int err;
 
 	err = clk_prepare_enable(priv->clk_ipg);
@@ -1206,10 +1207,41 @@ static int flexcan_open(struct net_device *dev)
 	if (err)
 		goto out_close;
 
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
+	else
+		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
+
+	priv->reg_imask1_default = 0;
+	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
+
+	priv->offload.mailbox_read = flexcan_mailbox_read;
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		u64 imask;
+
+		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
+		priv->offload.mb_last = FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST;
+
+		imask = GENMASK_ULL(priv->offload.mb_last,
+				    priv->offload.mb_first);
+		priv->reg_imask1_default |= imask;
+		priv->reg_imask2_default |= imask >> 32;
+
+		err = can_rx_offload_add_timestamp(dev, &priv->offload);
+	} else {
+		priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
+			FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
+		err = can_rx_offload_add_fifo(dev, &priv->offload,
+					      FLEXCAN_NAPI_WEIGHT);
+	}
+	if (err)
+		goto out_free_irq;
+
 	/* start chip and queuing */
 	err = flexcan_chip_start(dev);
 	if (err)
-		goto out_free_irq;
+		goto out_offload_del;
 
 	can_led_event(dev, CAN_LED_EVENT_OPEN);
 
@@ -1218,6 +1250,8 @@ static int flexcan_open(struct net_device *dev)
 
 	return 0;
 
+ out_offload_del:
+	can_rx_offload_del(&priv->offload);
  out_free_irq:
 	free_irq(dev->irq, dev);
  out_close:
@@ -1238,6 +1272,7 @@ static int flexcan_close(struct net_device *dev)
 	can_rx_offload_disable(&priv->offload);
 	flexcan_chip_stop(dev);
 
+	can_rx_offload_del(&priv->offload);
 	free_irq(dev->irq, dev);
 	clk_disable_unprepare(priv->clk_per);
 	clk_disable_unprepare(priv->clk_ipg);
@@ -1502,35 +1537,6 @@ static int flexcan_probe(struct platform_device *pdev)
 	priv->devtype_data = devtype_data;
 	priv->reg_xceiver = reg_xceiver;
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
-		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
-	else
-		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
-
-	priv->reg_imask1_default = 0;
-	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
-
-	priv->offload.mailbox_read = flexcan_mailbox_read;
-
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
-		u64 imask;
-
-		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
-		priv->offload.mb_last = FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST;
-
-		imask = GENMASK_ULL(priv->offload.mb_last, priv->offload.mb_first);
-		priv->reg_imask1_default |= imask;
-		priv->reg_imask2_default |= imask >> 32;
-
-		err = can_rx_offload_add_timestamp(dev, &priv->offload);
-	} else {
-		priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
-			FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
-		err = can_rx_offload_add_fifo(dev, &priv->offload, FLEXCAN_NAPI_WEIGHT);
-	}
-	if (err)
-		goto failed_offload;
-
 	err = register_flexcandev(dev);
 	if (err) {
 		dev_err(&pdev->dev, "registering netdev failed\n");
@@ -1550,7 +1556,6 @@ static int flexcan_probe(struct platform_device *pdev)
 
 	return 0;
 
- failed_offload:
  failed_register:
 	free_candev(dev);
 	return err;
@@ -1559,10 +1564,8 @@ static int flexcan_probe(struct platform_device *pdev)
 static int flexcan_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
-	struct flexcan_priv *priv = netdev_priv(dev);
 
 	unregister_flexcandev(dev);
-	can_rx_offload_del(&priv->offload);
 	free_candev(dev);
 
 	return 0;