Commit bf1bff11 authored by Enguerrand de Ribaucourt's avatar Enguerrand de Ribaucourt Committed by David S. Miller
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net: dsa: microchip: monitor potential faults in half-duplex mode 



The errata DS80000754 recommends monitoring potential faults in
half-duplex mode for the KSZ9477 family.

half-duplex is not very common so I just added a critical message
when the fault conditions are detected. The switch can be expected
to be unable to communicate anymore in these states and a software
reset of the switch would be required which I did not implement.

Fixes: b987e98e ("dsa: add DSA switch driver for Microchip KSZ9477")
Signed-off-by: default avatarEnguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d963c95b

drivers/net/dsa/microchip/ksz9477.c

+51 −0
Original line number Diff line number Diff line
@@ -427,6 +427,57 @@ void ksz9477_freeze_mib(struct ksz_device *dev, int port, bool freeze) 
	mutex_unlock(&p->mib.cnt_mutex);

}



int ksz9477_errata_monitor(struct ksz_device *dev, int port,

			   u64 tx_late_col)

{

	u32 pmavbc;

	u8 status;

	u16 pqm;

	int ret;



	ret = ksz_pread8(dev, port, REG_PORT_STATUS_0, &status);

	if (ret)

		return ret;

	if (!(FIELD_GET(PORT_INTF_SPEED_MASK, status) == PORT_INTF_SPEED_NONE) &&

	    !(status & PORT_INTF_FULL_DUPLEX)) {

		/* Errata DS80000754 recommends monitoring potential faults in

		 * half-duplex mode. The switch might not be able to communicate anymore

		 * in these states.

		 * If you see this message, please read the errata-sheet for more information:

		 * https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9477S-Errata-DS80000754.pdf

		 * To workaround this issue, half-duplex mode should be avoided.

		 * A software reset could be implemented to recover from this state.

		 */

		dev_warn_once(dev->dev,

			      "Half-duplex detected on port %d, transmission halt may occur\n",

			      port);

		if (tx_late_col != 0) {

			/* Transmission halt with late collisions */

			dev_crit_once(dev->dev,

				      "TX late collisions detected, transmission may be halted on port %d\n",

				      port);

		}

		ret = ksz_read8(dev, REG_SW_LUE_CTRL_0, &status);

		if (ret)

			return ret;

		if (status & SW_VLAN_ENABLE) {

			ret = ksz_pread16(dev, port, REG_PORT_QM_TX_CNT_0__4, &pqm);

			if (ret)

				return ret;

			ret = ksz_read32(dev, REG_PMAVBC, &pmavbc);

			if (ret)

				return ret;

			if ((FIELD_GET(PMAVBC_MASK, pmavbc) <= PMAVBC_MIN) ||

			    (FIELD_GET(PORT_QM_TX_CNT_M, pqm) >= PORT_QM_TX_CNT_MAX)) {

				/* Transmission halt with Half-Duplex and VLAN */

				dev_crit_once(dev->dev,

					      "resources out of limits, transmission may be halted\n");

			}

		}

	}

	return ret;

}



void ksz9477_port_init_cnt(struct ksz_device *dev, int port)

{

	struct ksz_port_mib *mib = &dev->ports[port].mib;

drivers/net/dsa/microchip/ksz9477.h

+2 −0
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ int ksz9477_port_mirror_add(struct ksz_device *dev, int port, 
			    bool ingress, struct netlink_ext_ack *extack);

void ksz9477_port_mirror_del(struct ksz_device *dev, int port,

			     struct dsa_mall_mirror_tc_entry *mirror);

int ksz9477_errata_monitor(struct ksz_device *dev, int port,

			   u64 tx_late_col);

void ksz9477_get_caps(struct ksz_device *dev, int port,

		      struct phylink_config *config);

int ksz9477_fdb_dump(struct ksz_device *dev, int port,

drivers/net/dsa/microchip/ksz9477_reg.h

+8 −2
Original line number Diff line number Diff line
@@ -843,8 +843,8 @@ 


#define REG_PORT_STATUS_0		0x0030



#define PORT_INTF_SPEED_M		0x3

#define PORT_INTF_SPEED_S		3

#define PORT_INTF_SPEED_MASK		GENMASK(4, 3)

#define PORT_INTF_SPEED_NONE		GENMASK(1, 0)

#define PORT_INTF_FULL_DUPLEX		BIT(2)

#define PORT_TX_FLOW_CTRL		BIT(1)

#define PORT_RX_FLOW_CTRL		BIT(0)
@@ -1168,6 +1168,11 @@ 
#define PORT_RMII_CLK_SEL		BIT(7)

#define PORT_MII_SEL_EDGE		BIT(5)



#define REG_PMAVBC			0x03AC



#define PMAVBC_MASK			GENMASK(26, 16)

#define PMAVBC_MIN			0x580



/* 4 - MAC */

#define REG_PORT_MAC_CTRL_0		0x0400
@@ -1495,6 +1500,7 @@ 


#define PORT_QM_TX_CNT_USED_S		0

#define PORT_QM_TX_CNT_M		(BIT(11) - 1)

#define PORT_QM_TX_CNT_MAX		0x200



#define REG_PORT_QM_TX_CNT_1__4		0x0A14

drivers/net/dsa/microchip/ksz_common.c

+11 −0
Original line number Diff line number Diff line
@@ -1382,6 +1382,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.tc_cbs_supported = true,

		.ops = &ksz9477_dev_ops,

		.phylink_mac_ops = &ksz9477_phylink_mac_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),

		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -1416,6 +1417,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.num_ipms = 8,

		.ops = &ksz9477_dev_ops,

		.phylink_mac_ops = &ksz9477_phylink_mac_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),

		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -1450,6 +1452,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.num_ipms = 8,

		.ops = &ksz9477_dev_ops,

		.phylink_mac_ops = &ksz9477_phylink_mac_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),

		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -1540,6 +1543,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.tc_cbs_supported = true,

		.ops = &ksz9477_dev_ops,

		.phylink_mac_ops = &ksz9477_phylink_mac_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),

		.reg_mib_cnt = MIB_COUNTER_NUM,
@@ -1820,6 +1824,7 @@ void ksz_r_mib_stats64(struct ksz_device *dev, int port) 
	struct rtnl_link_stats64 *stats;

	struct ksz_stats_raw *raw;

	struct ksz_port_mib *mib;

	int ret;



	mib = &dev->ports[port].mib;

	stats = &mib->stats64;
@@ -1861,6 +1866,12 @@ void ksz_r_mib_stats64(struct ksz_device *dev, int port) 
	pstats->rx_pause_frames = raw->rx_pause;



	spin_unlock(&mib->stats64_lock);



	if (dev->info->phy_errata_9477) {

		ret = ksz9477_errata_monitor(dev, port, raw->tx_late_col);

		if (ret)

			dev_err(dev->dev, "Failed to monitor transmission halt\n");

	}

}



void ksz88xx_r_mib_stats64(struct ksz_device *dev, int port)

drivers/net/dsa/microchip/ksz_common.h

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct ksz_chip_data { 
	bool tc_cbs_supported;

	const struct ksz_dev_ops *ops;

	const struct phylink_mac_ops *phylink_mac_ops;

	bool phy_errata_9477;

	bool ksz87xx_eee_link_erratum;

	const struct ksz_mib_names *mib_names;

	int mib_cnt;