diff mbox series

[5.10.y-cip,02/11] net: ravb: Fix R-Car RX frame size limit

Message ID 20250227145720.229324-3-paul.barker.ct@bp.renesas.com (mailing list archive)
State New
Headers show
Series ravb backports: MTU fix, VLAN & IPv6 support | expand

Commit Message

Paul Barker Feb. 27, 2025, 2:57 p.m. UTC
commit ec8234717db8589078d08b17efa528a235c61f4f upstream.

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 <s.shtylyov@omp.ru>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb_main.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index f0351db7c1b2..f8b58995e9b6 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -528,8 +528,16 @@  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 |