>From 97be2778e5eec620d7b65c30cda3a70b9af0a88c Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 27 Oct 2022 13:54:21 +0300 Subject: [PATCH 1/3] net: ftmac100: prepare data path for receiving single segment packets > 1514 Eliminate one check in the data path and move it elsewhere, to where our real limitation is. We'll want to start processing "too long" frames in the driver (currently there is a hardware MAC setting which drops theses). Signed-off-by: Vladimir Oltean --- drivers/net/ethernet/faraday/ftmac100.c | 29 ++++++++++--------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/drivers/net/ethernet/faraday/ftmac100.c b/drivers/net/ethernet/faraday/ftmac100.c index d95d78230828..8013f85fc148 100644 --- a/drivers/net/ethernet/faraday/ftmac100.c +++ b/drivers/net/ethernet/faraday/ftmac100.c @@ -218,11 +218,6 @@ static bool ftmac100_rxdes_crc_error(struct ftmac100_rxdes *rxdes) return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_CRC_ERR); } -static bool ftmac100_rxdes_frame_too_long(struct ftmac100_rxdes *rxdes) -{ - return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FTL); -} - static bool ftmac100_rxdes_runt(struct ftmac100_rxdes *rxdes) { return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RUNT); @@ -337,13 +332,7 @@ static bool ftmac100_rx_packet_error(struct ftmac100 *priv, error = true; } - if (unlikely(ftmac100_rxdes_frame_too_long(rxdes))) { - if (net_ratelimit()) - netdev_info(netdev, "rx frame too long\n"); - - netdev->stats.rx_length_errors++; - error = true; - } else if (unlikely(ftmac100_rxdes_runt(rxdes))) { + if (unlikely(ftmac100_rxdes_runt(rxdes))) { if (net_ratelimit()) netdev_info(netdev, "rx runt\n"); @@ -356,6 +345,11 @@ static bool ftmac100_rx_packet_error(struct ftmac100 *priv, netdev->stats.rx_length_errors++; error = true; } + /* + * FTMAC100_RXDES0_FTL is not an error, it just indicates that the + * frame is longer than 1518 octets. Receiving these is possible when + * we told the hardware not to drop them, via FTMAC100_MACCR_RX_FTL. + */ return error; } @@ -400,12 +394,13 @@ static bool ftmac100_rx_packet(struct ftmac100 *priv, int *processed) return true; } - /* - * It is impossible to get multi-segment packets - * because we always provide big enough receive buffers. - */ + /* We don't support multi-segment packets for now, so drop them. */ ret = ftmac100_rxdes_last_segment(rxdes); - BUG_ON(!ret); + if (unlikely(!ret)) { + netdev->stats.rx_length_errors++; + ftmac100_rx_drop_packet(priv); + return true; + } /* start processing */ skb = netdev_alloc_skb_ip_align(netdev, 128); -- 2.34.1