From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793483020; b=lMwpoz/2wtr3Rao9ftas6QH9T1Xf05gphYG2t7SKFMVXzclblSSIPhdjRK2jgwKcBnWd 9RguqX1bt3ShNSBCjjmCVzr2a6nBmgbUXKCw5LUyVoKgPqLL2V66l9Rgn9g5DiNJhgM1N XcuiLCgsDleRDYIq+S6ntbg3g2Eq+iYyMZethF9SdPaZo+m3C4aunZSDDxOPAqkOicuXc jE9KgLGrot9P6yVRzm0U1PjGgXJNFagWnv3bU4yVSyHYPRiJ5dmwrPRGIsoBPqi9pWD2J JslPIKrNJbUcEwyo5miAlLSdUET4SVIFk9D45yg5ONW6uOQgCGg6nedeqh1HRRFHzUQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793483020; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=IX+tK6TnvEFSZxT/chpScXK9DCCJeD/Zs96hYvJyHVU=; b=mZJTlBTfNUEu2HvLymJTYUF+67lOltEJwy7yb34e68x8740dUYKXFhv8Wjx3hsxxu/qY sERgLnu0drvVto4JFqMcTuOPWtexW00DMhRGsdAqU6SouKgSBU9qRI9zL+vwdg69QpK8w wHYu0Je+SH0AJXQ7JTYrhzFmrloVHAbQFpgp6mvIWx2OP19W2dZYol9ArwYKwTHoqpJoR yVBxjusLZH4Rc/D5BEb3q/U2VeVQgU9WHvHRmIG6YSkroKi/FPP7NhicYOuUS926i6h7R 34NN0E0MR5u15GOfVaW7tB6fuXkE1XKW4MmNRzeKL71/MUzosilMG2USekWV7N/GipA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CBjwRTu+; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E9951606A31A for ; Sat, 31 Oct 2026 21:43:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CBjwRTu+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CE421F000C1; Sat, 31 Oct 2026 21:43:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793483019; bh=IX+tK6TnvEFSZxT/chpScXK9DCCJeD/Zs96hYvJyHVU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=CBjwRTu+LpEtO108Cki0/vQFit3bUYjtVDnm3kw0XaRGcdyBBz7vFtB3MHwMq9U07 vyJc0XPnb+1yzF+CH/PtNJqnmPFYbpwt9lP08jp/VGz6YUbwAwJF84V/LCCEbzSk4f nDHbaskMJlzKZuU0tOQnN/eY/BZnvPqDnoSgApKa76TvwAN6LcdlucwfWGVnxt18wS Kfiy3Lzb+o2hFnUcTHuPswPDuGwfWDB30h8MCJqjDl9+oYtoyzPys89ltqOo5IWPY+ AhWqOXD6jFLIx3wbDsogAUTYhaa8s+kh4mSUmVcdy78QBgNRCu2pbjbLtR+weJUrBh R+W6oIY+3akSg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] usb: typec: ucsi: acpi: Assume UCSI 1.0 on Lenovo ThinkPad T14 Gen 2a Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?U3RhbmlzxYJhdyBUaXRlbmtv?= Cc: linux-usb@vger.kernel.org In-Reply-To: <20261031-ucsi-lenovo-t14g2a-v1-1-183751e63c02@resetko.pl> References: <20261031-ucsi-lenovo-t14g2a-v1-1-183751e63c02@resetko.pl> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 31 Oct 2026 21:43:39 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Stanis=C5=82aw Titenko >=20 > The Lenovo ThinkPad T14 Gen 2a exposes a functional UCSI ACPI PPM but > the firmware leaves the VERSION field of the UCSI mailbox at zero. >=20 > ucsi_register() rejects a zero version with -ENODEV, leaving the > system without registered USB Type-C connectors. Without an OPM, the > embedded controller does not complete DisplayPort Alternate Mode setup > when a USB-C dock or monitor that supplies power is connected after > boot, so the display stays dark while USB and charging work. >=20 > The mailbox uses the 48-byte UCSI 1.x layout, and the PPM works > correctly when UCSI 1.0 is assumed. >=20 > Add a DMI-specific UCSI operation for the ThinkPad T14 Gen 2a that > substitutes UCSI 1.0 only when firmware reports a zero version. > Preserve any valid non-zero firmware version. >=20 > Tested on a ThinkPad T14 Gen 2a with BIOS 1.33 (R1MET63W): both > Type-C connectors register, and plugging and replugging a USB-C > monitor with an integrated hub and power delivery brings up > DisplayPort Alternate Mode each time. >=20 > Reported-by: Daniel Dev > Closes: https://lore.kernel.org/linux-usb/b1Wn_eFvTFShGbd970WWl4CWhge_6P2= x7Wb6rab3QHNlE4OJ4p__O-QN3B6I-308ftr5oV5Zr7vywA0vdvmtNw6E0YJnVM2ek_5DcFnkXB= 0=3D@noex.uk/ > Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface") > Cc: stable@vger.kernel.org > Assisted-by: pi:claude-opus-5-5 > Signed-off-by: Stanis=C5=82aw Titenko Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261031-ucsi-lenov= o-t14g2a-v1-1-183751e63c02@resetko.pl?part=3D1