diff mbox series

[net,v3,2/2] net: ravb: Fix R-Car RX frame size limit

Message ID 20240918081839.259-3-paul.barker.ct@bp.renesas.com (mailing list archive)
State New
Delegated to: Geert Uytterhoeven
Headers show
Series Fix maximum TX/RX frame sizes in ravb driver | expand

Commit Message

Paul Barker Sept. 18, 2024, 8:18 a.m. UTC
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>
---
 drivers/net/ethernet/renesas/ravb_main.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Simon Horman Sept. 19, 2024, 7:27 a.m. UTC | #1
On Wed, Sep 18, 2024 at 09:18:39AM +0100, Paul Barker wrote:
> 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>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index e73cdba58516..d2a6518532f3 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 |