From: Ihor Urazov The HP ZBook 8 G2i 14 (board 8ED9) exposes a working UCSI ACPI PPM, but its UCSI VERSION field reads zero until the first command completes. ucsi_register() rejects a zero version with -ENODEV, so no Type-C ports are registered. The firmware's _DSM READ function (2) is a stub. The mailbox VERSION field is written only by the EC response handler, after a command completes, after which it reads 0x0100 (UCSI 1.0). The mailbox is 48 bytes with 16-byte MESSAGE_IN/MESSAGE_OUT fields, the UCSI 1.x layout, and _DSM function 5 is not implemented. Add a DMI-specific read_version for this board that substitutes the version the firmware itself reports, UCSI 1.0, only when VERSION reads zero. A non-zero firmware version is used as is. The same firmware defect on the HP ZBook Fury G1i 16 was discussed in "[RFC PATCH] usb: typec: ucsi: acpi: bootstrap PPM on HP systems with empty _DSM func 2" [1]. The defect was reported to HP as case 5166176673. Tested on an HP ZBook 8 G2i 14 with BIOS Y70 01.02.08, from a fresh boot where VERSION reads zero: three connectors register, the PD contract and alternate modes of a Thunderbolt dock are reported, and its DisplayPort output stays up across the PPM reset in ucsi_init(). Dock unplug/replug and s2idle suspend/resume update the connector state without errors. Link: https://lore.kernel.org/linux-usb/f3M_fpjtt8FxDqGKcA84vqXmRbKzCBfpCrIK4-jCWvIscER51zkD8qD8FYpz75qZw51rMDRSkUyYlrBvLvdM8CGRY2l8TFVvr4MC1LdTzbc=@interstellar.eu/ [1] Fixes: bdc62f2bae8f ("usb: typec: ucsi: Simplified registration and I/O API") Cc: stable@vger.kernel.org Cc: Francesco Orro Assisted-by: Claude:claude-opus-5-5 Reviewed-by: Heikki Krogerus Reviewed-by: Huang Wei Signed-off-by: Ihor Urazov --- Changes in v2: - Point Fixes: at bdc62f2bae8f, which added the zero-version check (Huang Wei) - Add Reviewed-by tags - Link to v1: https://patch.msgid.link/20261026-ucsi-hp-zbook-8-g2i-v1-1-91002e9ef073@gmail.com --- drivers/usb/typec/ucsi/ucsi_acpi.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c index 5697ccc24ec3..2421a92ecb0e 100644 --- a/drivers/usb/typec/ucsi/ucsi_acpi.c +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c @@ -148,6 +148,34 @@ static const struct ucsi_operations ucsi_acer_ops = { .async_control = ucsi_acpi_async_control }; +static int ucsi_hp_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; + + /* Firmware fills in VERSION (1.0) only after the first command completes */ + if (!*version) { + dev_warn(ua->dev, "UCSI version is zero, assuming 1.0\n"); + *version = UCSI_VERSION_1_0; + } + + return 0; +} + +static const struct ucsi_operations ucsi_hp_ops = { + .read_version = ucsi_hp_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) @@ -196,6 +224,13 @@ static const struct dmi_system_id ucsi_acpi_quirks[] = { }, .driver_data = (void *)&ucsi_acer_ops, }, + { + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "HP"), + DMI_MATCH(DMI_BOARD_NAME, "8ED9"), + }, + .driver_data = (void *)&ucsi_hp_ops, + }, { .matches = { DMI_MATCH(DMI_SYS_VENDOR, "LG Electronics"), --- base-commit: 21a7f44fd0765fcc5194130b28767786eba1d1e7 change-id: 20261026-ucsi-hp-zbook-8-g2i-4446ab6e5ed4 Best regards, -- Ihor Urazov