[PATCH 12/12] can: kvaser_pciefd: Use TX FIFO size read from CAN controller

[Jimmy Assarsson <extja@xxxxxxxxxx>]

Use the TX FIFO size read from CAN controller register, instead of using
hard coded value.

Signed-off-by: Jimmy Assarsson <extja@xxxxxxxxxx>
---
 drivers/net/can/kvaser_pciefd.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 0575bb84b280..5f67414e2875 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -640,8 +640,7 @@ static netdev_tx_t kvaser_pciefd_start_xmit(struct sk_buff *skb,
 	/* No room for a new message, stop the queue until at least one
 	 * successful transmit
 	 */
-	if (count >= KVASER_PCIEFD_CAN_TX_MAX_COUNT ||
-	    can->can.echo_skb[can->echo_idx])
+	if (count >= can->can.echo_skb_max || can->can.echo_skb[can->echo_idx])
 		netif_stop_queue(netdev);
 	spin_unlock_irqrestore(&can->echo_lock, irq_flags);
 
@@ -760,7 +759,7 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie)
 	for (i = 0; i < pcie->nr_channels; i++) {
 		struct net_device *netdev;
 		struct kvaser_pciefd_can *can;
-		u32 status, tx_nr_packets;
+		u32 status, tx_nr_packets, tx_nr_packets_max;
 
 		netdev = alloc_candev(sizeof(struct kvaser_pciefd_can),
 				      KVASER_PCIEFD_CAN_TX_MAX_COUNT);
@@ -786,17 +785,11 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie)
 		iowrite32(0, can->reg_base + KVASER_PCIEFD_KCAN_BUS_LOAD_REG);
 
 		tx_nr_packets = ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NR_PACKETS_REG);
-		if (((tx_nr_packets >> KVASER_PCIEFD_KCAN_TX_NR_PACKETS_MAX_SHIFT) &
-		      0xff) < KVASER_PCIEFD_CAN_TX_MAX_COUNT) {
-			dev_err(&pcie->pci->dev,
-				"Max Tx count is smaller than expected\n");
-
-			free_candev(netdev);
-			return -ENODEV;
-		}
+		tx_nr_packets_max =
+			(tx_nr_packets >> KVASER_PCIEFD_KCAN_TX_NR_PACKETS_MAX_SHIFT) & 0xff;
 
 		can->can.clock.freq = pcie->freq;
-		can->can.echo_skb_max = KVASER_PCIEFD_CAN_TX_MAX_COUNT;
+		can->can.echo_skb_max = min(KVASER_PCIEFD_CAN_TX_MAX_COUNT, tx_nr_packets_max - 1);
 		can->echo_idx = 0;
 		spin_lock_init(&can->echo_lock);
 		spin_lock_init(&can->lock);
@@ -1295,8 +1288,7 @@ static int kvaser_pciefd_handle_ack_packet(struct kvaser_pciefd *pcie,
 		len = can_get_echo_skb(can->can.dev, echo_idx, NULL);
 		count = ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NR_PACKETS_REG) & 0xff;
 
-		if (count < KVASER_PCIEFD_CAN_TX_MAX_COUNT &&
-		    netif_queue_stopped(can->can.dev))
+		if (count < can->can.echo_skb_max && netif_queue_stopped(can->can.dev))
 			netif_wake_queue(can->can.dev);
 
 		if (!one_shot_fail) {
-- 
2.40.0