On 2/6/2016 4:52 AM, Sergei Shtylyov wrote: > Hello. > > On 2/6/2016 12:52 AM, Troy Kisky wrote: > >> If you don't own it, you shouldn't write to it. >> >> Signed-off-by: Troy Kisky <troy.ki...@boundarydevices.com> >> --- >> 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. > [...] >> @@ -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); > > I think you can use "ligter" dma_wmb() in this case. >
Thanks for the review, I added a patch to the end of the series to address this. Troy
