[PATCH net-next] net: ixp4xx_eth: Specify min/max MTU
From: Linus Walleij <hidden>
Date: 2023-09-23 18:38:31
Also in:
lkml
Subsystem:
arm/intel ixp4xx arm architecture, networking drivers, the rest · Maintainers:
Linus Walleij, Imre Kaloz, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
As we don't specify the MTU in the driver, the framework will fall back to 1500 bytes and this doesn't work very well when we try to attach a DSA switch: eth1: mtu greater than device maximum ixp4xx_eth c800a000.ethernet eth1: error -22 setting MTU to 1504 to include DSA overhead I checked the developer docs and the hardware can actually do really big frames, so update the driver accordingly. Signed-off-by: Linus Walleij <redacted> --- drivers/net/ethernet/xscale/ixp4xx_eth.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c
index 3b0c5f177447..8f40287c8d58 100644
--- a/drivers/net/ethernet/xscale/ixp4xx_eth.c
+++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c@@ -24,6 +24,7 @@ #include <linux/dma-mapping.h> #include <linux/dmapool.h> #include <linux/etherdevice.h> +#include <linux/if_vlan.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/net_tstamp.h>
@@ -1488,6 +1489,13 @@ static int ixp4xx_eth_probe(struct platform_device *pdev) ndev->dev.dma_mask = dev->dma_mask; ndev->dev.coherent_dma_mask = dev->coherent_dma_mask; + /* Maximum frame size is 16320 bytes and includes VLAN and + * ethernet headers. See "IXP400 Software Programmer's Guide" + * section 10.3.2, page 161. + */ + ndev->min_mtu = ETH_MIN_MTU; + ndev->max_mtu = 16320 - VLAN_ETH_HLEN; + netif_napi_add_weight(ndev, &port->napi, eth_poll, NAPI_WEIGHT); if (!(port->npe = npe_request(NPE_ID(port->id))))
--- base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d change-id: 20230923-ixp4xx-eth-mtu-c041d7efe932 Best regards, -- Linus Walleij [off-list ref]