[PATCH] usb: typec: ucsi: acpi: Assume UCSI 1.2 on Acer Nitro ANV15-41

The Acer Nitro ANV15-41 exposes a functional UCSI ACPI PPM but
reports a UCSI VERSION value of zero.

ucsi_register() rejects a zero version with -ENODEV, leaving the
system without registered USB Type-C connectors.

The PPM works correctly when using the UCSI 1.2 layout. With UCSI
1.2 assumed, both Type-C connectors register correctly and USB Power
Delivery negotiation works.

Add a DMI-specific UCSI operation for the Acer Nitro ANV15-41 that
substitutes UCSI 1.2 only when firmware reports a zero version.
Preserve any valid non-zero firmware version.

Tested on an Acer Nitro ANV15-41 with BIOS V1.51.

Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Pannarat Wiriyaarritham <redacted>
---
 drivers/usb/typec/ucsi/ucsi_acpi.c | 34 ++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
index 18286d3e9..5697ccc24 100644
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c

@@ -121,6 +121,33 @@ static const struct ucsi_operations ucsi_acpi_ops = {
 	.async_control = ucsi_acpi_async_control
 };
 
+static int ucsi_acer_read_version(struct ucsi *ucsi, u16 *version)
+{
+	struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
+	int ret;
+
+	ret = ucsi_acpi_read_version(ucsi, version);
+	if (ret)
+		return ret;
+
+	if (!*version) {
+		dev_warn(ua->dev, "UCSI version is zero, assuming 1.2\n");
+		*version = UCSI_VERSION_1_2;
+	}
+
+	return 0;
+}
+
+static const struct ucsi_operations ucsi_acer_ops = {
+	.read_version = ucsi_acer_read_version,
+	.read_cci = ucsi_acpi_read_cci,
+	.poll_cci = ucsi_acpi_poll_cci,
+	.read_message_in = ucsi_acpi_read_message_in,
+	.write_message_out = ucsi_acpi_write_message_out,
+	.sync_control = ucsi_sync_control_common,
+	.async_control = ucsi_acpi_async_control
+};
+
 static int ucsi_gram_sync_control(struct ucsi *ucsi, u64 command, u32 *cci,
 				  void *val, size_t len, void *msg_out,
 				  size_t msg_out_size)

@@ -162,6 +189,13 @@ static const struct ucsi_operations ucsi_gram_ops = {
 };
 
 static const struct dmi_system_id ucsi_acpi_quirks[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro ANV15-41"),
+		},
+		.driver_data = (void *)&ucsi_acer_ops,
+	},
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "LG Electronics"),

-- 
2.55.0

On Thu, Sep 10, 2026 at 09:33:37AM +0700, Pannarat Wiriyaarritham wrote:

The Acer Nitro ANV15-41 exposes a functional UCSI ACPI PPM but
reports a UCSI VERSION value of zero.

ucsi_register() rejects a zero version with -ENODEV, leaving the
system without registered USB Type-C connectors.

The PPM works correctly when using the UCSI 1.2 layout. With UCSI
1.2 assumed, both Type-C connectors register correctly and USB Power
Delivery negotiation works.

Add a DMI-specific UCSI operation for the Acer Nitro ANV15-41 that
substitutes UCSI 1.2 only when firmware reports a zero version.
Preserve any valid non-zero firmware version.

Tested on an Acer Nitro ANV15-41 with BIOS V1.51.

Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Pannarat Wiriyaarritham <redacted>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

-- 
heikki