Re: [PATCH net-next 1/4] net: pse-pd: realtek-pse-mcu: ensure MCU does dynamic power management

[Kory Maincent <kory.maincent@bootlin.com>]

On 11/3/26 23:03, Jonas Jelonek wrote:
> From: Russell Senior <russell@personaltelco.net>
> 
> The MCU may have any power management mode configuration by default
> but the driver should ensure that the MCU performs dynamic power
> management with priorities as advertised. On certain devices, the
> default MCU configuration ships with another default, possibly
> preventing any power delivery.
> 
> Select the mode before deasserting the hardware port gate, so a failure
> to establish the management policy does not ungate the ports.
> 
> Signed-off-by: Russell Senior <russell@personaltelco.net>
> [jonas@jonasjelonek.de: adjust commit message, macro naming and comment;
>   change error handling and select the mode before ungating ports]
> Signed-off-by: Jonas Jelonek <jonas@jonasjelonek.de>
> ---
>   drivers/net/pse-pd/realtek-pse-mcu-core.c | 32 +++++++++++++++++++++++
>   1 file changed, 32 insertions(+)
> 
> diff --git a/drivers/net/pse-pd/realtek-pse-mcu-core.c b/drivers/net/pse-pd/realtek-pse-mcu-core.c
> index c70b09ca2012..f3fc67fe29d3 100644
> --- a/drivers/net/pse-pd/realtek-pse-mcu-core.c
> +++ b/drivers/net/pse-pd/realtek-pse-mcu-core.c
> @@ -68,10 +68,14 @@
>   /* Nominal PSE rail; 802.3at/bt operating range. */
>   #define RTPSE_MCU_PSE_VOLTAGE_UV		54000000
>   
> +/* RTPSE_MCU_CMD_SET_POWER_MANAGEMENT_MODE values */
> +#define RTPSE_MCU_POWER_MGMT_DYNAMIC_PRIO	0x02	/* dynamic, with port priority */
> +
>   enum rtpse_mcu_cmd {
>   	RTPSE_MCU_CMD_SET_GLOBAL_STATE,
>   	RTPSE_MCU_CMD_GET_SYSTEM_INFO,
>   	RTPSE_MCU_CMD_GET_EXT_CONFIG,
> +	RTPSE_MCU_CMD_SET_POWER_MANAGEMENT_MODE,
>   
>   	RTPSE_MCU_CMD_PORT_ENABLE,
>   	RTPSE_MCU_CMD_PORT_SET_POWER_LIMIT_TYPE,
> @@ -369,6 +373,26 @@ static int rtpse_mcu_set_global_state(struct rtpse_mcu_ctrl *pse, bool enable)
>   	return (resp.payload[0] == 0x0) ? 0 : -EIO;
>   }
>   
> +static int rtpse_mcu_set_power_management_mode(struct rtpse_mcu_ctrl *pse, u8 value)
> +{
> +	struct rtpse_mcu_msg req, resp;
> +	const struct rtpse_mcu_opcode *opc;
> +	int ret;
> +
> +	opc = &pse->dialect->opcode[RTPSE_MCU_CMD_SET_POWER_MANAGEMENT_MODE];
> +	if (!opc->valid)
> +		return -EOPNOTSUPP;
> +
> +	rtpse_mcu_msg_init(&req, opc->op);
> +	req.payload[0] = value;
> +
> +	ret = rtpse_mcu_do_xfer(pse, &req, &resp);
> +	if (ret)
> +		return ret;
> +
> +	return (resp.payload[0] == 0x0) ? 0 : -EIO;
> +}
> +
>   /* Port operations */
>   
>   static int rtpse_mcu_port_get_status(struct rtpse_mcu_ctrl *pse, unsigned int port,
> @@ -826,6 +850,12 @@ int rtpse_mcu_register(struct rtpse_mcu_ctrl *pse)
>   	if (ret)
>   		return ret;
>   
> +	/* ensure the MCU does dynamic power management with priorities */
> +	ret = rtpse_mcu_set_power_management_mode(pse, RTPSE_MCU_POWER_MGMT_DYNAMIC_PRIO);

Why do you pass RTPSE_MCU_POWER_MGMT_DYNAMIC_PRIO as parameter?
You are calling this function only once in the whole series so you can 
directly use it in the function.

pw-bot: cr

> +	if (ret)
> +		return dev_err_probe(pse->dev, ret,
> +				     "failed to set power management mode\n");
> +
>   	/*
>   	 * Some boards gate all ports through a hardware line; deassert it only
>   	 * after the MCU is confirmed, so a discover failure never ungates the
> @@ -944,6 +974,7 @@ static const struct rtpse_mcu_dialect rtpse_mcu_dialect_gen2 = {
>   		[RTPSE_MCU_CMD_SET_GLOBAL_STATE]	= RTPSE_MCU_OP(0x00),
>   		[RTPSE_MCU_CMD_GET_SYSTEM_INFO]		= RTPSE_MCU_OP(0x40),
>   		[RTPSE_MCU_CMD_GET_EXT_CONFIG]		= RTPSE_MCU_OP(0x4a),
> +		[RTPSE_MCU_CMD_SET_POWER_MANAGEMENT_MODE] = RTPSE_MCU_OP(0x10),
>   
>   		[RTPSE_MCU_CMD_PORT_ENABLE]		= RTPSE_MCU_OP(0x01),
>   		[RTPSE_MCU_CMD_PORT_SET_POWER_LIMIT_TYPE] = RTPSE_MCU_OP(0x12),
> @@ -964,6 +995,7 @@ static const struct rtpse_mcu_dialect rtpse_mcu_dialect_gen1 = {
>   	.opcode = {
>   		[RTPSE_MCU_CMD_GET_SYSTEM_INFO]		= RTPSE_MCU_OP(0x20),
>   		[RTPSE_MCU_CMD_GET_EXT_CONFIG]		= RTPSE_MCU_OP(0x2b),
> +		[RTPSE_MCU_CMD_SET_POWER_MANAGEMENT_MODE] = RTPSE_MCU_OP(0x17),
>   
>   		[RTPSE_MCU_CMD_PORT_ENABLE]		= RTPSE_MCU_OP(0x00),
>   		[RTPSE_MCU_CMD_PORT_SET_POWER_LIMIT_TYPE] = RTPSE_MCU_OP(0x15),

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com