From 8afb91acc4a3ea25ce15160df1fcab93b155b75e Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Thu, 26 Oct 2023 07:10:51 +0200 Subject: net: dsa: microchip: Ensure Stable PME Pin State for Wake-on-LAN Ensures a stable PME (Power Management Event) pin state by disabling PME on system start and enabling it on shutdown only if WoL (Wake-on-LAN) is configured. This is needed to avoid issues with some PMICs (Power Management ICs). Signed-off-by: Oleksij Rempel Reviewed-by: Vladimir Oltean Link: https://lore.kernel.org/r/20231026051051.2316937-6-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski --- drivers/net/dsa/microchip/ksz9477.c | 46 ++++++++++++++++++++++++++++++++++ drivers/net/dsa/microchip/ksz9477.h | 1 + drivers/net/dsa/microchip/ksz_common.c | 8 +++++- drivers/net/dsa/microchip/ksz_common.h | 1 + 4 files changed, 55 insertions(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 441b4597ef27..f24181086e16 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -197,6 +197,46 @@ int ksz9477_set_wol(struct ksz_device *dev, int port, return 0; } +/** + * ksz9477_wol_pre_shutdown - Prepares the switch device for shutdown while + * considering Wake-on-LAN (WoL) settings. + * @dev: The switch device structure. + * @wol_enabled: Pointer to a boolean which will be set to true if WoL is + * enabled on any port. + * + * This function prepares the switch device for a safe shutdown while taking + * into account the Wake-on-LAN (WoL) settings on the user ports. It updates + * the wol_enabled flag accordingly to reflect whether WoL is active on any + * port. + */ +void ksz9477_wol_pre_shutdown(struct ksz_device *dev, bool *wol_enabled) +{ + struct dsa_port *dp; + int ret; + + *wol_enabled = false; + + if (!dev->wakeup_source) + return; + + dsa_switch_for_each_user_port(dp, dev->ds) { + u8 pme_ctrl = 0; + + ret = ksz_pread8(dev, dp->index, REG_PORT_PME_CTRL, &pme_ctrl); + if (!ret && pme_ctrl) + *wol_enabled = true; + + /* make sure there are no pending wake events which would + * prevent the device from going to sleep/shutdown. + */ + ksz9477_handle_wake_reason(dev, dp->index); + } + + /* Now we are save to enable PME pin. */ + if (*wol_enabled) + ksz_write8(dev, REG_SW_PME_CTRL, PME_ENABLE); +} + static int ksz9477_wait_vlan_ctrl_ready(struct ksz_device *dev) { unsigned int val; @@ -1277,6 +1317,12 @@ int ksz9477_setup(struct dsa_switch *ds) /* enable global MIB counter freeze function */ ksz_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true); + /* Make sure PME (WoL) is not enabled. If requested, it will be + * enabled by ksz9477_wol_pre_shutdown(). Otherwise, some PMICs do not + * like PME events changes before shutdown. + */ + ksz_write8(dev, REG_SW_PME_CTRL, 0); + return 0; } diff --git a/drivers/net/dsa/microchip/ksz9477.h b/drivers/net/dsa/microchip/ksz9477.h index fa8d0318b437..ce1e656b800b 100644 --- a/drivers/net/dsa/microchip/ksz9477.h +++ b/drivers/net/dsa/microchip/ksz9477.h @@ -62,6 +62,7 @@ void ksz9477_get_wol(struct ksz_device *dev, int port, struct ethtool_wolinfo *wol); int ksz9477_set_wol(struct ksz_device *dev, int port, struct ethtool_wolinfo *wol); +void ksz9477_wol_pre_shutdown(struct ksz_device *dev, bool *wol_enabled); int ksz9477_port_acl_init(struct ksz_device *dev, int port); void ksz9477_port_acl_free(struct ksz_device *dev, int port); diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 3b48e42148a0..3fed406fb46a 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -321,6 +321,7 @@ static const struct ksz_dev_ops ksz9477_dev_ops = { .phylink_mac_link_up = ksz9477_phylink_mac_link_up, .get_wol = ksz9477_get_wol, .set_wol = ksz9477_set_wol, + .wol_pre_shutdown = ksz9477_wol_pre_shutdown, .config_cpu_port = ksz9477_config_cpu_port, .tc_cbs_set_cinc = ksz9477_tc_cbs_set_cinc, .enable_stp_addr = ksz9477_enable_stp_addr, @@ -3857,7 +3858,12 @@ EXPORT_SYMBOL(ksz_switch_alloc); */ void ksz_switch_shutdown(struct ksz_device *dev) { - if (dev->dev_ops->reset) + bool wol_enabled = false; + + if (dev->dev_ops->wol_pre_shutdown) + dev->dev_ops->wol_pre_shutdown(dev, &wol_enabled); + + if (dev->dev_ops->reset && !wol_enabled) dev->dev_ops->reset(dev); dsa_switch_shutdown(dev->ds); diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h index 14b4828f80a1..b7e8a403a132 100644 --- a/drivers/net/dsa/microchip/ksz_common.h +++ b/drivers/net/dsa/microchip/ksz_common.h @@ -378,6 +378,7 @@ struct ksz_dev_ops { struct ethtool_wolinfo *wol); int (*set_wol)(struct ksz_device *dev, int port, struct ethtool_wolinfo *wol); + void (*wol_pre_shutdown)(struct ksz_device *dev, bool *wol_enabled); void (*config_cpu_port)(struct dsa_switch *ds); int (*enable_stp_addr)(struct ksz_device *dev); int (*reset)(struct ksz_device *dev); -- cgit