From def52db470df28d6f43cacbd21137f03b9502073 Mon Sep 17 00:00:00 2001 From: Paul Barker Date: Tue, 16 Apr 2024 13:02:51 +0100 Subject: [PATCH] net: ravb: Count packets instead of descriptors in R-Car RX path MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 --- 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 ba01c8cc3c90..7d231d011bff 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -892,29 +892,24 @@ 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; @@ -960,7 +955,7 @@ 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; } @@ -995,9 +990,9 @@ 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 */ -- 2.39.5