From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi2-f12.google.com (mail-oi2-f12.google.com [74.125.231.204]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D6E151AEEB for ; Tue, 22 Sep 2026 21:32:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.204 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790112751; cv=none; b=TuBl3h+gjSV44twpG7lErIpSkTmF34DU3SLOg0qwbX5s2jTq974JoVNCmH6sOOxRMRWwdg0wWjUrPx8qPutGRrWIa2jQhbEDyeyPE//eW4bmhCYIRiWdvEbvQZgvvOBjPrp7P59APEzwLmrJbhREJ6r0pSynlYQ5z5DRrHzaPgY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790112751; c=relaxed/simple; bh=2WvlPAIbOGzbHSxW451eh2EWgHCeMfyZm2VVp4rH9Fo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tTSx0jCcr4uT7bs6kzCG2LLnKALAQpXeGfMIxjxgneBhBZQoJVBwU3Gl6z3zTd9Pfs0zJAezYZgg9GfbeoAGhtDyEepf84sYNhpHqmY+3uZrGPU+rPmCTsA4n5w0agEetIZUgClyKBRlwqglpNJ2ux6OWyRDrBkO81XoJ9jWM9U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=O/VYMqbZ; arc=none smtp.client-ip=74.125.231.204 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="O/VYMqbZ" Received: by mail-oi2-f12.google.com with SMTP id 46e09a7af769-7f4f0d298caso321062a34.0 for ; Tue, 22 Sep 2026 14:32:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790112739; x=1790717539; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=QDHhaSJenqoO/XxOlzKnAhXngtK3EcH5UtYe0wHr2pQ=; b=O/VYMqbZaieVBBW2hYUtA9maSTNTZCqIsRdEiVvUQmhD0AS+RjN+57nDZMC5fnmVXX xn4LOMA0GHSCNJGm+4ayNdAQwGNzaPEwiQI1MhT1Lm7fl5RW1UJKFtVPz4SAY/Fa7sTv ydTssnVoyQFgGglKGG6gey4motxa/zNudQPmeUIj0faS4218VF5a2qF6ZphyEo0RRt27 pV0uMgfiUsjZ+GccbAtKgk+b+9DgB89BKTiAQQTHKeLZ+gz+2ql+mL2DyFTprX73utnE nwH7CsUR2CPNFAUAX+pzj617+vtjKDMfxLEzu5IGJ2MAW3UNl4A2cjtQnYlguLhK731N 1XhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790112739; x=1790717539; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=QDHhaSJenqoO/XxOlzKnAhXngtK3EcH5UtYe0wHr2pQ=; b=GSIZamSnMuuO5ofPDftLeqF3Rqhk8xQhfOB4HXM/rwfpkzgk2iXH2kR3PNjOa0rSqr glu7auKE+HWuI6R4E6UjRCawwocsWkwEWBxwslH5Uk6seB3NyCKeTw2tw3bJj89/ngFD tM5h9oKSxuMZO0SHieA8f22u/gomtyf2PEYt7va+8kET4P29zhBPI4wCfLSFYrvZWgqj vXDJoN7Ide/AD2wtyZsAYHdXqUc6u+ZXhqeZy46DXU2dQXVdD+kYJccFyug0IS82OoFz /jFATH0llG58en6gkdwND/9S/+sXiqftfOQxdGVXz6Icvwh6hKG+eYjYw6PCkhMaWrKY Kd9g== X-Gm-Message-State: AFuF++kSreQIlDKngYZwSEEGsbGx9OhflOir7okO5jW61u1/+chThmrg pVsEFYO4EUBSpAfDlcUqlz9a5JSUa4hz14TWYbXfeMgo+aCP4EzmNR3XBYiD0qT+3vY= X-Gm-Gg: AYBFou2NanqZcaGjV43rRO+8v7CB6+Ub2lbNVdg6uojgitAHzHoJ3vJJSCtDbjOQ0Q0 5QpJAwfc56bbOZSNcx9qxE3f6IN47fDkvd5RN21u+iSjGjXVrPeAFEa91u8394ul8aWtWWZ/J5+ gcyxl194W85UbnMVUcsJqRIeboE3Jmj87IzNWGRVjLiL+RqJaydj1+kGb34ivt66tyvjMjrT+/y HBbHNIZFWncoIG5iFR1mdcChal52QVvCAQS9zHpDWsb1u7BOurPMe0gKamZifacmcIg9JAIzYcI auM10prMvSUwZbBSpsK7CNTpAHJWYJ04FlfNEt4LB26hUrPwKPXvE29X5MhfKfSiUQHQKVXXKc3 2jST/GcRA0KqBRJR7eebxZgh0LVMLx5weKsfFtjCs9KRZ9I70f2nKG0sJxxMLKw3cQRXuPEyLON 5+8+Pvm7qkSLU2OGp2zj45vJlEMXPaTdYezwnmIt+NAltTWBAunYp/LQtTbXluvAEIEdn9FOtzD FVUJCe8Z0qYfSBv X-Received: by 2002:a05:6830:2b2b:b0:801:6bec:ff18 with SMTP id 46e09a7af769-815f007097emr1057735a34.2.1790112739471; Tue, 22 Sep 2026 14:32:19 -0700 (PDT) Received: from localhost ([35.11.35.209]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-816044c858bsm947461a34.19.2026.09.22.14.32.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Sep 2026 14:32:19 -0700 (PDT) From: sjunhyuk1@gmail.com To: linux-usb@vger.kernel.org, platform-driver-x86@vger.kernel.org Cc: Heikki Krogerus , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Subject: Re: [BUG] HP OMEN Transcend 14 (board 8E41): GPU power ceiling on 65W USB-C charger is non-deterministic across sessions (25W vs ~65W) Date: Tue, 22 Sep 2026 17:32:18 -0400 Message-ID: <20260922213218.5334-1-sjunhyuk1@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260922192312.40607-1-sjunhyuk1@gmail.com> References: <20260922192312.40607-1-sjunhyuk1@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Important correction to my earlier report: I ran the same charger through HP's OMEN Gaming Hub on Windows (same laptop, dual-boot) and found this is very likely *intended* HP behavior, not a bug: "Performance settings are overridden by system defaults while using battery or a low-power AC adapter. Connect a compatible AC adapter to restore normal system performance." HP's own first-party software explicitly classifies the 65W charger as a "low-power AC adapter" and documents that it intentionally overrides performance down. So the 25W ceiling itself is apparently by design, not a fault. More importantly: **it also reproduces on Windows.** Same laptop, same 65W charger, Windows test session: 25W ceiling from cold boot, OMEN Gaming Hub's presence/absence made no difference, and the full poweroff+physical-unplug/replug workaround that reliably restored 65W on Linux did *not* recover it on Windows in this test (stayed at 25W for a 60-second FurMark run, 60/60 samples). So my claim that "I don't see this at all under Windows" was wrong - apologies for the bad data point. What's still odd, and still possibly Linux/kernel-relevant: on Linux, the same 65W charger sometimes lands on ~65W instead of the (apparently intended) 25W, non-deterministically across boots/ reconnects, and stays fixed at whichever value for the rest of that session. If 25W is the intended default for this adapter class, the ~65W outcome looks like an unintended bypass of HP's low-power- adapter policy rather than a "fix" - I just don't yet know whether that bypass happens on Windows too (only tested one Windows boot session so far, which stayed at 25W throughout). So the interesting question is probably no longer "why is this laptop sometimes clamped to 25W" (looks intended) but "what makes the negotiated result non-deterministic instead of consistently matching HP's stated policy" - which could still be something in the UCSI/PD negotiation path. Sorry for the noise, and thanks for reading this far.