From 1d63864299cafa7c8cbde56491c9932afdbff7ea Mon Sep 17 00:00:00 2001 From: Paul Barker Date: Wed, 18 Sep 2024 09:18:38 +0100 Subject: [PATCH 1/2] net: ravb: Fix maximum TX frame size for GbEth devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The datasheets for all SoCs using the GbEth IP specify a maximum transmission frame size of 1.5 kByte. I've confirmed through internal discussions that support for 1522 byte frames has been validated, which allows us to support the default MTU of 1500 bytes after reserving space for the Ethernet header, frame checksums and an optional VLAN tag. Fixes: 2e95e08ac009 ("ravb: Add rx_max_buf_size to struct ravb_hw_info") Reviewed-by: Niklas Söderlund Reviewed-by: Sergey Shtylyov Signed-off-by: Paul Barker Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni --- drivers/net/ethernet/renesas/ravb.h | 1 + drivers/net/ethernet/renesas/ravb_main.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h index 9893c91af1050..a7de5cf6b3174 100644 --- a/drivers/net/ethernet/renesas/ravb.h +++ b/drivers/net/ethernet/renesas/ravb.h @@ -1052,6 +1052,7 @@ struct ravb_hw_info { netdev_features_t net_features; int stats_len; u32 tccr_mask; + u32 tx_max_frame_size; u32 rx_max_frame_size; u32 rx_buffer_size; u32 rx_desc_size; diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index c7ec23688d56a..e73cdba585165 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2674,6 +2674,7 @@ static const struct ravb_hw_info ravb_gen2_hw_info = { .net_features = NETIF_F_RXCSUM, .stats_len = ARRAY_SIZE(ravb_gstrings_stats), .tccr_mask = TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, + .tx_max_frame_size = SZ_2K, .rx_max_frame_size = SZ_2K, .rx_buffer_size = SZ_2K + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), @@ -2696,6 +2697,7 @@ static const struct ravb_hw_info ravb_gen3_hw_info = { .net_features = NETIF_F_RXCSUM, .stats_len = ARRAY_SIZE(ravb_gstrings_stats), .tccr_mask = TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, + .tx_max_frame_size = SZ_2K, .rx_max_frame_size = SZ_2K, .rx_buffer_size = SZ_2K + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), @@ -2721,6 +2723,7 @@ static const struct ravb_hw_info ravb_gen4_hw_info = { .net_features = NETIF_F_RXCSUM, .stats_len = ARRAY_SIZE(ravb_gstrings_stats), .tccr_mask = TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, + .tx_max_frame_size = SZ_2K, .rx_max_frame_size = SZ_2K, .rx_buffer_size = SZ_2K + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), @@ -2770,6 +2773,7 @@ static const struct ravb_hw_info gbeth_hw_info = { .net_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM, .stats_len = ARRAY_SIZE(ravb_gstrings_stats_gbeth), .tccr_mask = TCCR_TSRQ0, + .tx_max_frame_size = 1522, .rx_max_frame_size = SZ_8K, .rx_buffer_size = SZ_2K, .rx_desc_size = sizeof(struct ravb_rx_desc), @@ -2981,7 +2985,7 @@ static int ravb_probe(struct platform_device *pdev) priv->avb_link_active_low = of_property_read_bool(np, "renesas,ether-link-active-low"); - ndev->max_mtu = info->rx_max_frame_size - + ndev->max_mtu = info->tx_max_frame_size - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN); ndev->min_mtu = ETH_MIN_MTU; From ec8234717db8589078d08b17efa528a235c61f4f Mon Sep 17 00:00:00 2001 From: Paul Barker Date: Wed, 18 Sep 2024 09:18:39 +0100 Subject: [PATCH 2/2] net: ravb: Fix R-Car RX frame size limit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The RX frame size limit should not be based on the current MTU setting. Instead it should be based on the hardware capabilities. While we're here, improve the description of the receive frame length setting as suggested by Niklas. Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") Reviewed-by: Sergey Shtylyov Reviewed-by: Niklas Söderlund Signed-off-by: Paul Barker Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni --- drivers/net/ethernet/renesas/ravb_main.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index e73cdba585165..d2a6518532f37 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -555,8 +555,16 @@ static void ravb_emac_init_gbeth(struct net_device *ndev) static void ravb_emac_init_rcar(struct net_device *ndev) { - /* Receive frame limit set register */ - ravb_write(ndev, ndev->mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN, RFLR); + struct ravb_private *priv = netdev_priv(ndev); + + /* Set receive frame length + * + * The length set here describes the frame from the destination address + * up to and including the CRC data. However only the frame data, + * excluding the CRC, are transferred to memory. To allow for the + * largest frames add the CRC length to the maximum Rx descriptor size. + */ + ravb_write(ndev, priv->info->rx_max_frame_size + ETH_FCS_LEN, RFLR); /* EMAC Mode: PAUSE prohibition; Duplex; RX Checksum; TX; RX */ ravb_write(ndev, ECMR_ZPF | ECMR_DM |