From be293467b87c30cfdb24f74dcb225b693e436121 Mon Sep 17 00:00:00 2001 From: Troy Kisky Date: Fri, 5 Feb 2016 14:52:49 -0700 Subject: [PATCH] net: fec: don't transfer ownership until descriptor write is complete If you don't own it, you shouldn't write to it. Signed-off-by: Troy Kisky Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index ca2708d..97ca72a 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -390,6 +390,10 @@ fec_enet_txq_submit_frag_skb(struct fec_enet_priv_tx_q *txq, bdp->cbd_bufaddr = cpu_to_fec32(addr); bdp->cbd_datlen = cpu_to_fec16(frag_len); + /* Make sure the updates to rest of the descriptor are + * performed before transferring ownership. + */ + wmb(); bdp->cbd_sc = cpu_to_fec16(status); } @@ -499,6 +503,10 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq, bdp->cbd_datlen = cpu_to_fec16(buflen); bdp->cbd_bufaddr = cpu_to_fec32(addr); + /* Make sure the updates to rest of the descriptor are performed before + * transferring ownership. + */ + wmb(); /* Send it on its way. Tell FEC it's ready, interrupt when done, * it's the last BD of the frame, and to put the CRC on the end. @@ -1475,7 +1483,6 @@ rx_processing_done: /* Mark the buffer empty */ status |= BD_ENET_RX_EMPTY; - bdp->cbd_sc = cpu_to_fec16(status); if (fep->bufdesc_ex) { struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp; @@ -1484,6 +1491,11 @@ rx_processing_done: ebdp->cbd_prot = 0; ebdp->cbd_bdu = 0; } + /* Make sure the updates to rest of the descriptor are + * performed before transferring ownership. + */ + wmb(); + bdp->cbd_sc = cpu_to_fec16(status); /* Update BD pointer to next entry */ bdp = fec_enet_get_nextdesc(bdp, &rxq->bd); -- 2.7.4