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net: dsa: microchip: ksz9477: implement MTU configuration

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This chips supports two ways to configure max MTU size:
- by setting SW_LEGAL_PACKET_DISABLE bit: if this bit is 0 allowed packed size
  will be between 64 and bytes 1518. If this bit is 1, it will accept
  packets up to 2000 bytes.
- by setting SW_JUMBO_PACKET bit. If this bit is set, the chip will
  ignore SW_LEGAL_PACKET_DISABLE value and use REG_SW_MTU__2 register to
  configure MTU size.

Current driver has disabled SW_JUMBO_PACKET bit and activates
SW_LEGAL_PACKET_DISABLE. So the switch will pass all packets up to 2000 without
any way to configure it.

By providing port_change_mtu we are switch to SW_JUMBO_PACKET way and will
be able to configure MTU up to ~9000.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20220308135857.1119028-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Oleksij Rempel 2022-03-08 14:58:57 +01:00 committed by Jakub Kicinski
parent e58bc86463
commit e18058ea99
3 changed files with 38 additions and 2 deletions
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36
drivers/net/dsa/microchip/ksz9477.c
View File

@ -11,6 +11,7 @@
#include <linux/platform_data/microchip-ksz.h>
#include <linux/phy.h>
#include <linux/if_bridge.h>
#include <linux/if_vlan.h>
#include <net/dsa.h>
#include <net/switchdev.h>
@ -182,6 +183,29 @@ static void ksz9477_port_cfg32(struct ksz_device *dev, int port, int offset,
bits, set ? bits : 0);
}
static int ksz9477_change_mtu(struct dsa_switch *ds, int port, int mtu)
{
struct ksz_device *dev = ds->priv;
u16 frame_size, max_frame = 0;
int i;
frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
/* Cache the per-port MTU setting */
dev->ports[port].max_frame = frame_size;
for (i = 0; i < dev->port_cnt; i++)
max_frame = max(max_frame, dev->ports[i].max_frame);
return regmap_update_bits(dev->regmap[1], REG_SW_MTU__2,
REG_SW_MTU_MASK, max_frame);
}
static int ksz9477_max_mtu(struct dsa_switch *ds, int port)
{
return KSZ9477_MAX_FRAME_SIZE - VLAN_ETH_HLEN - ETH_FCS_LEN;
}
static int ksz9477_wait_vlan_ctrl_ready(struct ksz_device *dev)
{
unsigned int val;
@ -1416,8 +1440,14 @@ static int ksz9477_setup(struct dsa_switch *ds)
/* Do not work correctly with tail tagging. */
ksz_cfg(dev, REG_SW_MAC_CTRL_0, SW_CHECK_LENGTH, false);
/* accept packet up to 2000bytes */
ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_LEGAL_PACKET_DISABLE, true);
/* Enable REG_SW_MTU__2 reg by setting SW_JUMBO_PACKET */
ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_JUMBO_PACKET, true);
/* Now we can configure default MTU value */
ret = regmap_update_bits(dev->regmap[1], REG_SW_MTU__2, REG_SW_MTU_MASK,
VLAN_ETH_FRAME_LEN + ETH_FCS_LEN);
if (ret)
return ret;
ksz9477_config_cpu_port(ds);
@ -1464,6 +1494,8 @@ static const struct dsa_switch_ops ksz9477_switch_ops = {
.port_mirror_add = ksz9477_port_mirror_add,
.port_mirror_del = ksz9477_port_mirror_del,
.get_stats64 = ksz9477_get_stats64,
.port_change_mtu = ksz9477_change_mtu,
.port_max_mtu = ksz9477_max_mtu,
};
static u32 ksz9477_get_port_addr(int port, int offset)

3
drivers/net/dsa/microchip/ksz9477_reg.h
View File

@ -176,6 +176,7 @@
#define REG_SW_MAC_ADDR_5 0x0307
#define REG_SW_MTU__2 0x0308
#define REG_SW_MTU_MASK GENMASK(13, 0)
#define REG_SW_ISP_TPID__2 0x030A
@ -1662,4 +1663,6 @@
/* 148,800 frames * 67 ms / 100 */
#define BROADCAST_STORM_VALUE 9969
#define KSZ9477_MAX_FRAME_SIZE 9000
#endif /* KSZ9477_REGS_H */

1
drivers/net/dsa/microchip/ksz_common.h
View File

@ -41,6 +41,7 @@ struct ksz_port {
struct ksz_port_mib mib;
phy_interface_t interface;
u16 max_frame;
};
struct ksz_device {