[PATCH net-next 02/10] docs: net: fix minor issues with driver guide

[Jakub Kicinski <kuba@kernel.org>]

Update the driver documentation TX queue example to match current APIs:

- use the ring-local tx_ring_mask field in drv_tx_avail()
- stop the selected netdev_queue with netif_tx_stop_queue() instead of
  stopping queue 0 with netif_stop_queue()

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/networking/driver.rst | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/driver.rst b/Documentation/networking/driver.rst
index 4f5dfa9c022e..195a916dc0de 100644
--- a/Documentation/networking/driver.rst
+++ b/Documentation/networking/driver.rst
@@ -51,7 +51,7 @@ Instead it must maintain the queue properly.  For example,
 	{
 		u32 used = READ_ONCE(dr->prod) - READ_ONCE(dr->cons);
 
-		return dr->tx_ring_size - (used & bp->tx_ring_mask);
+		return dr->tx_ring_size - (used & dr->tx_ring_mask);
 	}
 
 	static netdev_tx_t drv_hard_start_xmit(struct sk_buff *skb,
@@ -69,7 +69,7 @@ Instead it must maintain the queue properly.  For example,
 		//...
 		/* This should be a very rare race - log it. */
 		if (drv_tx_avail(dr) <= skb_shinfo(skb)->nr_frags + 1) {
-			netif_stop_queue(dev);
+			netif_tx_stop_queue(txq);
 			netdev_warn(dev, "Tx Ring full when queue awake!\n");
 			return NETDEV_TX_BUSY;
 		}
@@ -103,6 +103,9 @@ Lockless queue stop / wake helper macros
 .. kernel-doc:: include/net/netdev_queues.h
    :doc: Lockless queue stopping / waking helpers.
 
+The standard macros like netif_txq_maybe_stop(), netif_txq_try_stop() etc.
+are well tested, prefer them over local synchronization schemes.
+
 No exclusive ownership
 ----------------------
 
-- 
2.54.0