[net-next,5/5] net: gemini: Indicate that we can handle jumboframes

Message ID 20180630161806.24312-5-linus.walleij@linaro.org
State Superseded
Headers show
Series
  • [net-next,1/5] net: gemini: Look up L3 maxlen from table
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Commit Message

Linus Walleij June 30, 2018, 4:18 p.m.
The hardware supposedly handles frames up to 10236 bytes and
implements .ndo_change_mtu() so accept 10236 minus the ethernet
header for a VLAN tagged frame on the netdevices.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 drivers/net/ethernet/cortina/gemini.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.17.1

Comments

Andrew Lunn July 1, 2018, 7:58 a.m. | #1
On Sat, Jun 30, 2018 at 06:18:06PM +0200, Linus Walleij wrote:
> The hardware supposedly handles frames up to 10236 bytes and

> implements .ndo_change_mtu() so accept 10236 minus the ethernet

> header for a VLAN tagged frame on the netdevices.

> 

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

> ---

>  drivers/net/ethernet/cortina/gemini.c | 5 +++++

>  1 file changed, 5 insertions(+)

> 

> diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c

> index 79324bbfd768..ae475393e4ac 100644

> --- a/drivers/net/ethernet/cortina/gemini.c

> +++ b/drivers/net/ethernet/cortina/gemini.c

> @@ -2473,6 +2473,11 @@ static int gemini_ethernet_port_probe(struct platform_device *pdev)

>  

>  	netdev->hw_features = GMAC_OFFLOAD_FEATURES;

>  	netdev->features |= GMAC_OFFLOAD_FEATURES | NETIF_F_GRO;

> +	/* We can handle jumbo frames up to 10236 bytes so, let's accept

> +	 * payloads of 10236 bytes minus VLAN and ethernet header

> +	 */

> +	netdev->min_mtu = 256;

> +	netdev->max_mtu = 10236 - VLAN_ETH_HLEN;


Hi Linus

The commit message does not mention the min mtu you set here. Where
does 256 come from?

Thanks
     Andrew

Patch

diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 79324bbfd768..ae475393e4ac 100644
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -2473,6 +2473,11 @@  static int gemini_ethernet_port_probe(struct platform_device *pdev)
 
 	netdev->hw_features = GMAC_OFFLOAD_FEATURES;
 	netdev->features |= GMAC_OFFLOAD_FEATURES | NETIF_F_GRO;
+	/* We can handle jumbo frames up to 10236 bytes so, let's accept
+	 * payloads of 10236 bytes minus VLAN and ethernet header
+	 */
+	netdev->min_mtu = 256;
+	netdev->max_mtu = 10236 - VLAN_ETH_HLEN;
 
 	port->freeq_refill = 0;
 	netif_napi_add(netdev, &port->napi, gmac_napi_poll,