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authorBrian King <brking@linux.vnet.ibm.com>2019-07-15 16:41:50 -0500
committerDavid S. Miller <davem@davemloft.net>2019-07-21 12:29:25 -0700
commitea811b795df24644a8eb760b493c43fba4450677 (patch)
treef5d8400080437a0ba12ca8f66d7e031b17c99ad1
parent0cea0e1148fe134a4a3aaf0b1496f09241fb943a (diff)
downloadlinux-ea811b795df24644a8eb760b493c43fba4450677.tar.bz2
bnx2x: Prevent load reordering in tx completion processing
This patch fixes an issue seen on Power systems with bnx2x which results in the skb is NULL WARN_ON in bnx2x_free_tx_pkt firing due to the skb pointer getting loaded in bnx2x_free_tx_pkt prior to the hw_cons load in bnx2x_tx_int. Adding a read memory barrier resolves the issue. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 656ed80647f0..e2be5a685130 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -285,6 +285,9 @@ int bnx2x_tx_int(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata)
hw_cons = le16_to_cpu(*txdata->tx_cons_sb);
sw_cons = txdata->tx_pkt_cons;
+ /* Ensure subsequent loads occur after hw_cons */
+ smp_rmb();
+
while (sw_cons != hw_cons) {
u16 pkt_cons;