diff mbox series

[net,v3,6/9] net: axienet: Fix TX ring slot available check

Message ID 20220118214132.357349-7-robert.hancock@calian.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series Xilinx axienet fixes | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers fail 1 blamed authors not CCed: ariane.keller@tik.ee.ethz.ch; 1 maintainers not CCed: ariane.keller@tik.ee.ethz.ch
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Robert Hancock Jan. 18, 2022, 9:41 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 3f92001bacaf..85fe2b3bd37a 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;
 }