From: Jiajun Wu <b06...@freescale.com> commit 7583605b6d29f1f7f6fc505b883328089f3485ad ("ucc_geth: Fix empty TX queue processing") fixed empty TX queue mishandling, but didn't account another corner case: when TX queue becomes full.
Without this patch the driver will stop transmiting when TX queue becomes full since 'bd == ugeth->txBd[txQ]' actually checks for two things: queue empty or full. Let's better check for NULL skb, which unambiguously signals an empty queue. Signed-off-by: Jiajun Wu <b06...@freescale.com> Signed-off-by: Anton Vorontsov <avoront...@ru.mvista.com> Cc: Stable <sta...@vger.kernel.org> [2.6.32] --- On Mon, Jan 11, 2010 at 07:52:26PM +0800, Wu Jiajun-B06378 wrote: > Yes,'if (!skb)' is enough. > You can reproduce transmitting stopping if you use > 'if ((bd == ugeth->txBd[txQ])' and run ipforwarding with MTU=64 > 1Gbps 100%linerate. OK, let's resend the patch with just !skb check? drivers/net/ucc_geth.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index 96bdc0b..eb8fe7e 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -3279,13 +3279,12 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ) /* Handle the transmitted buffer and release */ /* the BD to be used with the current frame */ - if (bd == ugeth->txBd[txQ]) /* queue empty? */ + skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]; + if (!skb) break; dev->stats.tx_packets++; - skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]; - if (skb_queue_len(&ugeth->rx_recycle) < RX_BD_RING_LEN && skb_recycle_check(skb, ugeth->ug_info->uf_info.max_rx_buf_length + -- 1.6.5.7 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev