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 DE14D175A5 for ; Sat, 18 Jul 2026 17:22:38 +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=1784395359; cv=none; b=k9PZKGD7/HeHDnP7t9plJFhR6PmPef28MAPv+Dxag9YN8JUMfjiaP0lYIfZZjR3RU3AqDC6gtjJYUtqJntjIbwlsSFsyt3e6jHn4XgzH1+vs9CDPb+m3ifq0sqULRmiZLLHbWFzG/8BMoy4UNIqr2DBfI7zoU86KhIsGcaAzSTY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784395359; c=relaxed/simple; bh=yV0aERIwYPImae+1vw3n7z7EsTChcETr/TVxFvpngZc=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=SCeqxczIQwbfA/h6JJoLrsOM0rX1PnnYE9w850B0VhzMMQ+7AxfLPVfQWD72OrHmhuSuIMpsUUizzL1QoT3G8QvpM8KXQJccuDsZqc9Ol5SukYiGHW0zgk8/fhMLRCNfaTpXjy0+sU9HqVdwoL1QPE6kx5vXapsif++Ay/6/4wA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Fxz8wmOd; 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="Fxz8wmOd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EE011F000E9; Sat, 18 Jul 2026 17:22:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784395358; bh=iDXSzANRqREQJJWLCafTfXdsbNq8zt+hhWDsZIot8SQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Fxz8wmOdCtTtu2VEVRnMSwM/TaH/x22FNcLdCl10MKoovka8BpzjjY3SpRQ9NczuX ANotyXely8z43TiQa/2KsKCM+WFCe5FmddR+s4KBgXyoFcOlcbibWE7Sesi+nGQmfJ Xi5AgkYnE3dMCXhLtgFoGrxAxUpxDEdrjVHKO5EozZQElyHTOiuaHtoR2rnC2Awhb2 3iUT5XWoVmFX/8r0Wd0SwcbURmxCifxlF6ShGBaZJ+4Bk3XDNY67urdthY7dbYlbtG Wh9KbUng/x5FDdGasZ2xWiHx8QYU8n/PCRelaKk1AIq73DiOKXoM648p9xZJ8tuONb I6x8JGKRP1UIg== From: sashiko-bot@kernel.org Subject: Re: [PATCH 5/5] arm64: dts: qcom: x1: disable ps883x USB4 capability Reply-To: sashiko-reviews@lists.linux.dev To: "Jens Glathe" Cc: devicetree@vger.kernel.org, robh@kernel.org, conor+dt@kernel.org In-Reply-To: <20260718-ps883x-disable-usb4-v1-5-cec86d0b909e@oldschoolsolutions.biz> References: <20260718-ps883x-disable-usb4-v1-0-cec86d0b909e@oldschoolsolutions.biz> <20260718-ps883x-disable-usb4-v1-5-cec86d0b909e@oldschoolsolutions.biz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 18 Jul 2026 17:22:37 +0000 Message-Id: <20260718172238.3EE011F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] The `parade,disable-usb4` property encodes a transient software wo= rkaround into the Device Tree and breaks non-fallback docks by intentionall= y failing retimer configuration. -- --- Patch [5]: [PATCH 5/5] arm64: dts: qcom: x1: disable ps883x USB4 capabi= lity --- commit c967f56ff3b6574dc86834616a0288179a8a0cd3 Author: Jens Glathe arm64: dts: qcom: x1: disable ps883x USB4 capability Add the "parade,disable-usb4" property to the PS883x node so that the retimer driver treats USB4 as USB3. This allows the combo PHY to remain in a DP-capable mode, restoring working DisplayPort output over the dock while keeping USB functional. [ ... ] > diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi = b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi > index 5d49df41be02a..c8bfb38c64ad5 100644 > --- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi > +++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi > @@ -895,6 +895,8 @@ typec-mux@8 { > orientation-switch; > retimer-switch; > =20 > + parade,disable-usb4; [Severity: High] The commit message mentions this is a temporary platform workaround for mis= sing software support. Does this encode a transient OS driver limitation into the device tree? Device trees typically describe fixed hardware capabilities. Will adding th= is property permanently mask the hardware's actual capabilities and cause issu= es=20 for future OS updates once proper USB4 DP tunneling is available? Also, looking at how the retimer driver handles this property: drivers/usb/typec/mux/ps883x.c:ps883x_set() { ... case TYPEC_MODE_USB4: if (retimer->disable_usb4) { dev_info(&retimer->client->dev, "USB4 disabled via DT property, rejecting USB4 mode\n"= ); return -EOPNOTSUPP; } ... } By returning -EOPNOTSUPP, this intentionally skips retimer configuration and leaves the physical link broken. While some docks might detect the broken link, time out, and fall back to DP Alt Mode + USB3, what happens with docks that don't implement this fallback behavior?=20 Could this approach result in completely broken USB and DisplayPort functionality on non-fallback docks when the PMIC autonomously negotiates USB4? [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260718-ps883x-dis= able-usb4-v1-0-cec86d0b909e@oldschoolsolutions.biz?part=3D5