From patchwork Mon Jul 29 14:30:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Barker X-Patchwork-Id: 13745049 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BC41C3DA7E for ; Mon, 29 Jul 2024 14:30:48 +0000 (UTC) Received: from relmlie5.idc.renesas.com (relmlie5.idc.renesas.com [210.160.252.171]) by mx.groups.io with SMTP id smtpd.web10.57356.1722263436472009546 for ; Mon, 29 Jul 2024 07:30:38 -0700 Authentication-Results: mx.groups.io; dkim=none (message not signed); spf=pass (domain: bp.renesas.com, ip: 210.160.252.171, mailfrom: paul.barker.ct@bp.renesas.com) X-IronPort-AV: E=Sophos;i="6.09,246,1716217200"; d="scan'208";a="213905662" Received: from unknown (HELO relmlir5.idc.renesas.com) ([10.200.68.151]) by relmlie5.idc.renesas.com with ESMTP; 29 Jul 2024 23:30:38 +0900 Received: from ree-du1sdd5.ree.adwin.renesas.com (unknown [10.226.105.7]) by relmlir5.idc.renesas.com (Postfix) with ESMTP id 63FD94017D89; Mon, 29 Jul 2024 23:30:36 +0900 (JST) From: Paul Barker To: cip-dev@lists.cip-project.org, Nobuhiro Iwamatsu , Pavel Machek Cc: Biju Das , Lad Prabhakar Subject: [PATCH 5.10.y cip 10/11] net: ravb: Count packets instead of descriptors in R-Car RX path Date: Mon, 29 Jul 2024 14:30:10 +0000 Message-Id: <20240729143011.1920068-11-paul.barker.ct@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240729143011.1920068-1-paul.barker.ct@bp.renesas.com> References: <20240729143011.1920068-1-paul.barker.ct@bp.renesas.com> MIME-Version: 1.0 List-Id: X-Webhook-Received: from li982-79.members.linode.com [45.33.32.79] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Mon, 29 Jul 2024 14:30:48 -0000 X-Groupsio-URL: https://lists.cip-project.org/g/cip-dev/message/16643 commit def52db470df28d6f43cacbd21137f03b9502073 upstream. The units of "work done" in the RX path should be packets instead of descriptors. Descriptors which are used by the hardware to record error conditions or are empty in the case of a DMA mapping error should not count towards our RX work budget. Also make the limit variable unsigned as it can never be negative. Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") Signed-off-by: Paul Barker Reviewed-by: Sergey Shtylyov Reviewed-by: Niklas Söderlund Signed-off-by: Paolo Abeni Signed-off-by: Paul Barker --- drivers/net/ethernet/renesas/ravb_main.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index 7e87417a1909..eaf99b456166 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -890,29 +890,24 @@ static bool ravb_rx_rcar(struct net_device *ndev, int *quota, int q) struct ravb_private *priv = netdev_priv(ndev); const struct ravb_hw_info *info = priv->info; int entry = priv->cur_rx[q] % priv->num_rx_ring[q]; - int boguscnt = (priv->dirty_rx[q] + priv->num_rx_ring[q]) - - priv->cur_rx[q]; struct net_device_stats *stats = &priv->stats[q]; struct ravb_ex_rx_desc *desc; + unsigned int limit, i; struct sk_buff *skb; dma_addr_t dma_addr; struct timespec64 ts; + int rx_packets = 0; u8 desc_status; u16 pkt_len; - int limit; - boguscnt = min(boguscnt, *quota); - limit = boguscnt; + limit = priv->dirty_rx[q] + priv->num_rx_ring[q] - priv->cur_rx[q]; desc = &priv->rx_ring[q].ex_desc[entry]; - while (desc->die_dt != DT_FEMPTY) { + for (i = 0; i < limit && rx_packets < *quota && desc->die_dt != DT_FEMPTY; i++) { /* Descriptor type must be checked before all other reads */ dma_rmb(); desc_status = desc->msc; pkt_len = le16_to_cpu(desc->ds_cc) & RX_DS; - if (--boguscnt < 0) - break; - /* We use 0-byte descriptors to mark the DMA mapping errors */ if (!pkt_len) continue; @@ -958,7 +953,7 @@ static bool ravb_rx_rcar(struct net_device *ndev, int *quota, int q) if (ndev->features & NETIF_F_RXCSUM) ravb_rx_csum(skb); napi_gro_receive(&priv->napi[q], skb); - stats->rx_packets++; + rx_packets++; stats->rx_bytes += pkt_len; } @@ -993,9 +988,9 @@ static bool ravb_rx_rcar(struct net_device *ndev, int *quota, int q) desc->die_dt = DT_FEMPTY; } - *quota -= limit - (++boguscnt); - - return boguscnt <= 0; + stats->rx_packets += rx_packets; + *quota -= rx_packets; + return *quota == 0; } /* Packet receive function for Ethernet AVB */