From: Brian King Date: Mon, 15 Jul 2019 21:41:50 +0000 (-0500) Subject: bnx2x: Prevent load reordering in tx completion processing X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ea811b795df24644a8eb760b493c43fba4450677;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: David S. Miller --- 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;