Re: [PATCH] usb: typec: ucsi: do not register UCSI on Lenovo Legion Pro 7 16IAX10H

[Alex <alex@alstergee.com>]

Applied on top of Ubuntu 26.04's linux-source-7.0.0 (7.0.0-30.30, kernel
7.0.0-30-generic).  Hunks applied cleanly at -18 line offset. Built just
ucsi_acpi.ko out-of-tree against the running kernel's headers, MOK-signed,
inserted at runtime.

Probe correctly hits the ignore list and refuses to register:

   ucsi_acpi USBC000:00: UCSI implementation in firmware is broken, ignoring

/sys/class/power_supply/ucsi-source-psy-* is absent afterwards (probe
returned before ucsi_register).  A USB-C PD charger connected during the
swap remained connected across the module reload: BAT0 status stayed
Charging, capacity climbed 70% -> 71% during the test, ADP0 online = 1
throughout.  Consistent with the EC handling PD autonomously.

BIOS is Q7CN78WW (2026-04), same behaviour as reported.

Tested-by: Alex Bartz <alex@alstergee.com>

Thanks.

On 8/25/26 9:46 PM, Huang Wei wrote:
> The EC firmware of the Lenovo Legion Pro 7 16IAX10H (DMI product name
> 83F5) has a broken UCSI implementation: GET_PDOS returns no source
> capabilities, GET_CONNECTOR_STATUS reports an incomplete RDO, and any
> UCSI traffic disturbs the EC's autonomous USB-C Power Delivery
> negotiation. With ucsi_acpi bound, chargers connect only briefly and
> then drop, and voltage_now reads 0; with the driver blacklisted, the
> EC negotiates full PD contracts on its own and charging works normally.
>
> The problem is unaffected by BIOS updates up to Q7CN78WW (2026-04).
> The AMD sibling Legion Pro 7 16AFR10H (product name 83RU) reportedly
> uses the same EC firmware, but it is left out of the quirk until the
> failure is confirmed on that model.
>
> Skip probe on this machine, which is equivalent to the blacklist
> workaround the reporter verified to restore charging.
>
> Reported-by: Alex Bartz <alex@alstergee.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221142
> Signed-off-by: Huang Wei <huangwei@kylinos.cn>
> ---
>   drivers/usb/typec/ucsi/ucsi_acpi.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
> index 18286d3e9cc5..9f36f8cfce4a 100644
> --- a/drivers/usb/typec/ucsi/ucsi_acpi.c
> +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
> @@ -173,6 +173,21 @@ static const struct dmi_system_id ucsi_acpi_quirks[] = {
>   	{ }
>   };
>   
> +/*
> + * Platforms with a completely broken UCSI implementation in firmware.
> + * Do not register UCSI at all on these machines.
> + */
> +static const struct dmi_system_id ucsi_acpi_ignore[] = {
> +	{
> +		/* Lenovo Legion Pro 7 16IAX10H: broken EC UCSI firmware */
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "83F5"),
> +		},
> +	},
> +	{ }
> +};
> +
>   static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
>   {
>   	struct ucsi_acpi *ua = data;
> @@ -199,6 +214,12 @@ static int ucsi_acpi_probe(struct platform_device *pdev)
>   	if (adev->dep_unmet)
>   		return -EPROBE_DEFER;
>   
> +	if (dmi_check_system(ucsi_acpi_ignore)) {
> +		dev_info(&pdev->dev,
> +			 "UCSI implementation in firmware is broken, ignoring\n");
> +		return -ENODEV;
> +	}
> +
>   	ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
>   	if (!ua)
>   		return -ENOMEM;