Commit 46e31db5 authored by Oleksij Rempel's avatar Oleksij Rempel Committed by David S. Miller
Browse files

net: macb: fix negative max_mtu size for sama5d3 



JML register on probe will return zero . This register is configured
later on macb_init_hw() which is called on open.
Since we have zero, after header and FCS length subtraction we will get
negative max_mtu size. This issue was affecting DSA drivers with MTU support
(for example KSZ9477).

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2c0ab32b

drivers/net/ethernet/cadence/macb_main.c

+2 −2
Original line number Diff line number Diff line
@@ -4913,8 +4913,8 @@ static int macb_probe(struct platform_device *pdev) 


	/* MTU range: 68 - 1500 or 10240 */

	dev->min_mtu = GEM_MTU_MIN_SIZE;

	if (bp->caps & MACB_CAPS_JUMBO)

		dev->max_mtu = gem_readl(bp, JML) - ETH_HLEN - ETH_FCS_LEN;

	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;