From 8f3d044b34fe99b894046edb84605456195cabc0 Mon Sep 17 00:00:00 2001 From: "Kory Maincent (Dent Project)" Date: Mon, 13 Oct 2025 16:05:33 +0200 Subject: [PATCH] net: pse-pd: pd692x0: Preserve PSE configuration across reboots Detect when PSE hardware is already configured (user byte == 42) and skip hardware initialization to prevent power interruption to connected devices during system reboots. Previously, the driver would always reconfigure the PSE hardware on probe, causing a port matrix reflash that resulted in temporary power loss to all connected devices. This change maintains power continuity by preserving existing configuration when the PSE has been previously initialized. Signed-off-by: Kory Maincent Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251013-feature_pd692x0_reboot_keep_conf-v2-3-68ab082a93dd@bootlin.com Signed-off-by: Jakub Kicinski --- drivers/net/pse-pd/pd692x0.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/drivers/net/pse-pd/pd692x0.c b/drivers/net/pse-pd/pd692x0.c index 782b1abf94cb..134435e90073 100644 --- a/drivers/net/pse-pd/pd692x0.c +++ b/drivers/net/pse-pd/pd692x0.c @@ -30,6 +30,8 @@ #define PD692X0_FW_MIN_VER 5 #define PD692X0_FW_PATCH_VER 5 +#define PD692X0_USER_BYTE 42 + enum pd692x0_fw_state { PD692X0_FW_UNKNOWN, PD692X0_FW_OK, @@ -80,6 +82,7 @@ enum { PD692X0_MSG_GET_PORT_PARAM, PD692X0_MSG_GET_POWER_BANK, PD692X0_MSG_SET_POWER_BANK, + PD692X0_MSG_SET_USER_BYTE, /* add new message above here */ PD692X0_MSG_CNT @@ -103,6 +106,7 @@ struct pd692x0_priv { bool last_cmd_key; unsigned long last_cmd_key_time; + bool cfg_saved; enum ethtool_c33_pse_admin_state admin_state[PD692X0_MAX_PIS]; struct regulator_dev *manager_reg[PD692X0_MAX_MANAGERS]; int manager_pw_budget[PD692X0_MAX_MANAGERS]; @@ -193,6 +197,12 @@ static const struct pd692x0_msg pd692x0_msg_template_list[PD692X0_MSG_CNT] = { .key = PD692X0_KEY_CMD, .sub = {0x07, 0x0b, 0x57}, }, + [PD692X0_MSG_SET_USER_BYTE] = { + .key = PD692X0_KEY_PRG, + .sub = {0x41, PD692X0_USER_BYTE}, + .data = {0x4e, 0x4e, 0x4e, 0x4e, + 0x4e, 0x4e, 0x4e, 0x4e}, + }, }; static u8 pd692x0_build_msg(struct pd692x0_msg *msg, u8 echo) @@ -1233,6 +1243,15 @@ static void pd692x0_managers_free_pw_budget(struct pd692x0_priv *priv) } } +static int +pd692x0_save_user_byte(struct pd692x0_priv *priv) +{ + struct pd692x0_msg msg, buf; + + msg = pd692x0_msg_template_list[PD692X0_MSG_SET_USER_BYTE]; + return pd692x0_sendrecv_msg(priv, &msg, &buf); +} + static int pd692x0_setup_pi_matrix(struct pse_controller_dev *pcdev) { struct pd692x0_priv *priv = to_pd692x0_priv(pcdev); @@ -1268,9 +1287,16 @@ static int pd692x0_setup_pi_matrix(struct pse_controller_dev *pcdev) if (ret) goto err_managers_req_pw; - ret = pd692x0_hw_conf_init(priv); - if (ret) - goto err_managers_req_pw; + /* Do not init the conf if it is already saved */ + if (!priv->cfg_saved) { + ret = pd692x0_hw_conf_init(priv); + if (ret) + goto err_managers_req_pw; + + ret = pd692x0_save_user_byte(priv); + if (ret) + goto err_managers_req_pw; + } pd692x0_of_put_managers(priv, manager); kfree(manager); @@ -1793,6 +1819,9 @@ static int pd692x0_i2c_probe(struct i2c_client *client) } } + if (buf.data[2] == PD692X0_USER_BYTE) + priv->cfg_saved = true; + priv->np = dev->of_node; priv->pcdev.nr_lines = PD692X0_MAX_PIS; priv->pcdev.owner = THIS_MODULE; -- 2.47.3