From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A78F406261; Mon, 24 Aug 2026 11:31:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787571119; cv=none; b=Gb8HLdD/kvmLq76mwIcaWu2sC8BcjuBOloOMITxHtwfzZyk4nx51GSbhz2/FMgHPFqwRdrQCzcXlFbFDf7udWYi1ogdDLet7ZpTu7lfuHU/u+TOUr+FsVABKW6VYt/WAcyPtm92yua7HPFoeJe8wxHwZ/PZ++cXHs9ijTI3QV3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787571119; c=relaxed/simple; bh=EYMYdwXdg6z7MIH9WURjs406goCzCbmpieTCp02weOM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=i8Gg9tA+ywz4seW1yt3BCB4e1PW/jhJ3pvENG+bRb5fZkgnmUV3e0PttzRt/u9zWIPhVMcvCwzMKrU4hFmgELcG0x+AXwVSQIreTtYO4/6CtDF8mnTr/Gws7kKLBpkCLkrjNoezIerUhxe0YkAhe9rqkkHe2namULj/NNlrbduc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dzdmdI7Q; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dzdmdI7Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42C391F000E9; Mon, 24 Aug 2026 11:31:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787571118; bh=wcOBll4DRF2xHRnbLSjT/re7AM4u1F1OT5C5VGFZo0g=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=dzdmdI7Qdki6AlneDAImOc4I3xAnNkzgD2ICMBZXLez7HyBHGoBZVys8kjryn/wAR Cmus39rIBJfPecfqsfoHmTxjaDfjIUtppuuLZA6SujN4FRaGuXyJyIQZ8ZmcSoZyVW wziTsfwrO36EgdXzZPXiGmCizxFGh2URu6i0di/hFKT8UCFv2k26mtEXGj3NS8rfLw YIRI7sTH2On37SRQbfeEIkc2DpG72cpWNKEPpYGJDxvxbZHXRjmcGFZ1rb705kVvY8 lvXo15keVK7TNU2bIBOljwobhL0FYFbfVy87UlWi23F0Ytp4+UTHU+rVnIvFaucKMQ AX10YL93vaZHQ== Message-ID: <20514e95-60ea-48de-979b-87b1dd7bcc12@kernel.org> Date: Mon, 24 Aug 2026 13:31:54 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] usb: typec: tbt: Correct swapped TBT adapter type values To: Heikki Krogerus Cc: Benson Leung , Abhishek Pandit-Subedi , Jameson Thies , Andrei Kuchynski , Tzung-Bi Shih , Guenter Roeck , Bjorn Andersson , Konrad Dybcio , Greg Kroah-Hartman , chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org References: <20260818-b4-tbt-legacy-fix-v1-1-797831e3df3f@kernel.org> Content-Language: en-US From: Sven Peter In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/24/26 13:11, Heikki Krogerus wrote: > On Tue, Aug 18, 2026 at 06:20:03PM +0200, Sven Peter wrote: >> Table F-10 of the USB Type-C Cable and Connector Specification R2.5 on >> page 412 defines bit 16 of the TBT3 Device Discover Mode VDO as 0 = TBT3 >> Adapter and 1 = TBT2 Legacy Adapter. Linux has those two swapped since >> their original introduction in commit ca469c292edc ("usb: typec: Add >> definitions for Thunderbolt 3 Alternate Mode"). >> >> ChromiumOS EC's include/usb_pd_tbt.h has them the correct way around >> and references the USB Type-C ECN "Thunderbolt 3 Compatibility Updates" >> as fixing an error where they were originally swapped which is presumably >> where the wrong order originally came from. >> >> I've also confirmed the correct mapping with an Apple Thunderbolt 3 >> to Thunderbolt 2 adapter which does set bit 16 in that VDO. >> >> Swap the two values and update all users. Also rename the old defines >> so that no user accidentally ends up with an inverted value. >> No functional change. >> >> Link: https://usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-25 >> Link: https://chromium.googlesource.com/chromiumos/platform/ec/+/db93814b6e73c8545d23714fe0674c10814d901a/include/usb_pd_tbt.h#90 >> Signed-off-by: Sven Peter > Shouldn't this be marked as a fix? I left it out deliberately together with Cc: stable because there's no functional change but I can just add it if you want to. The original commit is already in the message. > > Reviewed-by: Heikki Krogerus Thanks! Sven