[PATCH net-next 1/1] net: macb: increase max_mtu for oversized frames

vtpieter
2024-08-12T09:07:13Z

From: Pieter Van Trappen <pieter.van.trappen@cern.ch>

Increase max_mtu from 1500 to 1518 bytes when not configured for jumbo
frames. Use 1536 as a starting point as documented in macb.h for
oversized (big) frames, which is the configuration applied in case
jumbo frames capability is not configured; ref. macb_main.c.

Signed-off-by: Pieter Van Trappen <pieter.van.trappen@cern.ch>
---
drivers/net/ethernet/cadence/macb_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 95e8742dce1d..c46fce4a9175 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -5119,12 +5119,12 @@ static int macb_probe(struct platform_device *pdev)
goto err_out_free_netdev;
}

- /* MTU range: 68 - 1500 or 10240 */
+ /* MTU range: 68 - 1518 or 10240 */
dev->min_mtu = GEM_MTU_MIN_SIZE;
if ((bp->caps & MACB_CAPS_JUMBO) && bp->jumbo_max_len)
dev->max_mtu = bp->jumbo_max_len - ETH_HLEN - ETH_FCS_LEN;
else
- dev->max_mtu = ETH_DATA_LEN;
+ dev->max_mtu = 1536 - ETH_HLEN - ETH_FCS_LEN;

if (bp->caps & MACB_CAPS_BD_RD_PREFETCH) {
val = GEM_BFEXT(RXBD_RDBUFF, gem_readl(bp, DCFG10));

base-commit: c4e82c025b3f2561823b4ba7c5f112a2005f442b
--
2.43.0