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

[Huang Wei <huangwei@kylinos.cn>]

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;
-- 
2.25.1