Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965175AbcCIXUq (ORCPT ); Wed, 9 Mar 2016 18:20:46 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41183 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965021AbcCIXS7 (ORCPT ); Wed, 9 Mar 2016 18:18:59 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Manfred Rudigier , "David S . Miller" , Luis Henriques , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 116/138] net: dp83640: Fix tx timestamp overflow handling. Date: Wed, 9 Mar 2016 15:14:03 -0800 Message-Id: <1457565265-15195-117-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457565265-15195-1-git-send-email-kamal@canonical.com> References: <1457565265-15195-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2476 Lines: 72 3.13.11-ckt36 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Manfred Rudigier commit 81e8f2e930fe76b9814c71b9d87c30760b5eb705 upstream. PHY status frames are not reliable, the PHY may not be able to send them during heavy receive traffic. This overflow condition is signaled by the PHY in the next status frame, but the driver did not make use of it. Instead it always reported wrong tx timestamps to user space after an overflow happened because it assigned newly received tx timestamps to old packets in the queue. This commit fixes this issue by clearing the tx timestamp queue every time an overflow happens, so that no timestamps are delivered for overflow packets. This way time stamping will continue correctly after an overflow. Signed-off-by: Manfred Rudigier Acked-by: Richard Cochran Signed-off-by: David S. Miller Signed-off-by: Luis Henriques Signed-off-by: Kamal Mostafa --- drivers/net/phy/dp83640.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c index d2907a6..be37c04 100644 --- a/drivers/net/phy/dp83640.c +++ b/drivers/net/phy/dp83640.c @@ -698,6 +698,11 @@ static void decode_rxts(struct dp83640_private *dp83640, { struct rxts *rxts; unsigned long flags; + u8 overflow; + + overflow = (phy_rxts->ns_hi >> 14) & 0x3; + if (overflow) + pr_debug("rx timestamp queue overflow, count %d\n", overflow); spin_lock_irqsave(&dp83640->rx_lock, flags); @@ -721,6 +726,7 @@ static void decode_txts(struct dp83640_private *dp83640, struct skb_shared_hwtstamps shhwtstamps; struct sk_buff *skb; u64 ns; + u8 overflow; /* We must already have the skb that triggered this. */ @@ -730,6 +736,17 @@ static void decode_txts(struct dp83640_private *dp83640, pr_debug("have timestamp but tx_queue empty\n"); return; } + + overflow = (phy_txts->ns_hi >> 14) & 0x3; + if (overflow) { + pr_debug("tx timestamp queue overflow, count %d\n", overflow); + while (skb) { + skb_complete_tx_timestamp(skb, NULL); + skb = skb_dequeue(&dp83640->tx_queue); + } + return; + } + ns = phy2txts(phy_txts); memset(&shhwtstamps, 0, sizeof(shhwtstamps)); shhwtstamps.hwtstamp = ns_to_ktime(ns); -- 2.7.0