diff mbox series

[net,v2,6/9] net: axienet: Fix TX ring slot available check

Message ID 20220112173700.873002-7-robert.hancock@calian.com (mailing list archive)
State New, archived
Headers show
Series Xilinx axienet fixes | expand

Commit Message

Robert Hancock Jan. 12, 2022, 5:36 p.m. UTC 
The check for whether a TX ring slot was available was incorrect,
since a slot which had been loaded with transmit data but the device had
not started transmitting would be treated as available, potentially
causing non-transmitted slots to be overwritten. The control field in
the descriptor should be checked, rather than the status field (which may
only be updated when the device completes the entry).

Fixes: 8a3b7a252dca9 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 8a60219d3bfb..ee8d656200b8 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -643,7 +643,6 @@  static int axienet_free_tx_chain(struct net_device *ndev, u32 first_bd,
 		if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK))
 			dev_consume_skb_irq(cur_p->skb);
 
-		cur_p->cntrl = 0;
 		cur_p->app0 = 0;
 		cur_p->app1 = 0;
 		cur_p->app2 = 0;
@@ -651,6 +650,7 @@  static int axienet_free_tx_chain(struct net_device *ndev, u32 first_bd,
 		cur_p->skb = NULL;
 		/* ensure our transmit path and device don't prematurely see status cleared */
 		wmb();
+		cur_p->cntrl = 0;
 		cur_p->status = 0;
 
 		if (sizep)
@@ -713,7 +713,7 @@  static inline int axienet_check_tx_bd_space(struct axienet_local *lp,
 	/* Ensure we see all descriptor updates from device or TX IRQ path */
 	rmb();
 	cur_p = &lp->tx_bd_v[(lp->tx_bd_tail + num_frag) % lp->tx_bd_num];
-	if (cur_p->status & XAXIDMA_BD_STS_ALL_MASK)
+	if (cur_p->cntrl)
 		return NETDEV_TX_BUSY;
 	return 0;
 }