From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932931AbbA2Jxu (ORCPT ); Thu, 29 Jan 2015 04:53:50 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:44798 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759007AbbA2JDd (ORCPT ); Thu, 29 Jan 2015 04:03:33 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Dumazet , "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 064/176] alx: fix alx_poll() Date: Wed, 28 Jan 2015 15:28:14 +0100 Message-Id: X-Mailer: git-send-email 2.2.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 7a05dc64e2e4c611d89007b125b20c0d2a4d31a5 ] Commit d75b1ade567f ("net: less interrupt masking in NAPI") uncovered wrong alx_poll() behavior. A NAPI poll() handler is supposed to return exactly the budget when/if napi_complete() has not been called. It is also supposed to return number of frames that were received, so that netdev_budget can have a meaning. Also, in case of TX pressure, we still have to dequeue received packets : alx_clean_rx_irq() has to be called even if alx_clean_tx_irq(alx) returns false, otherwise device is half duplex. Signed-off-by: Eric Dumazet Fixes: d75b1ade567f ("net: less interrupt masking in NAPI") Reported-by: Oded Gabbay Bisected-by: Oded Gabbay Tested-by: Oded Gabbay Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- drivers/net/ethernet/atheros/alx/main.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c index 6305a5d29db2..754ac8ef2484 100644 --- a/drivers/net/ethernet/atheros/alx/main.c +++ b/drivers/net/ethernet/atheros/alx/main.c @@ -184,15 +184,16 @@ static void alx_schedule_reset(struct alx_priv *alx) schedule_work(&alx->reset_wk); } -static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) +static int alx_clean_rx_irq(struct alx_priv *alx, int budget) { struct alx_rx_queue *rxq = &alx->rxq; struct alx_rrd *rrd; struct alx_buffer *rxb; struct sk_buff *skb; u16 length, rfd_cleaned = 0; + int work = 0; - while (budget > 0) { + while (work < budget) { rrd = &rxq->rrd[rxq->rrd_read_idx]; if (!(rrd->word3 & cpu_to_le32(1 << RRD_UPDATED_SHIFT))) break; @@ -203,7 +204,7 @@ static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) ALX_GET_FIELD(le32_to_cpu(rrd->word0), RRD_NOR) != 1) { alx_schedule_reset(alx); - return 0; + return work; } rxb = &rxq->bufs[rxq->read_idx]; @@ -243,7 +244,7 @@ static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) } napi_gro_receive(&alx->napi, skb); - budget--; + work++; next_pkt: if (++rxq->read_idx == alx->rx_ringsz) @@ -258,21 +259,22 @@ next_pkt: if (rfd_cleaned) alx_refill_rx_ring(alx, GFP_ATOMIC); - return budget > 0; + return work; } static int alx_poll(struct napi_struct *napi, int budget) { struct alx_priv *alx = container_of(napi, struct alx_priv, napi); struct alx_hw *hw = &alx->hw; - bool complete = true; unsigned long flags; + bool tx_complete; + int work; - complete = alx_clean_tx_irq(alx) && - alx_clean_rx_irq(alx, budget); + tx_complete = alx_clean_tx_irq(alx); + work = alx_clean_rx_irq(alx, budget); - if (!complete) - return 1; + if (!tx_complete || work == budget) + return budget; napi_complete(&alx->napi); @@ -284,7 +286,7 @@ static int alx_poll(struct napi_struct *napi, int budget) alx_post_write(hw); - return 0; + return work; } static irqreturn_t alx_intr_handle(struct alx_priv *alx, u32 intr) -- 2.2.2