From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 3732E4D5988; Mon, 28 Sep 2026 13:59:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790603991; cv=none; b=JYtZXn8llU8QxMOPtoES+oYxopBuhdPNmO8yBXmJgRQEQ0nWwpC064LiUpzPIsije/LQiZO0nk7w+2rVw6vfqP6tjQ0HgmfyZEe8DskHnLDC+/qhBEyQIwsgkU4ew8+sjE8bJHV7CPe5TwLoCxpVkp2cRgnFQ86sTWaMOC8r3Cs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790603991; c=relaxed/simple; bh=oK3jZxxDr0BnpPbmFCjbTWLPyFqxlCPZlscEIjM9pLE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=S8F/yFLeuO7dMwy/0D1cu0lB2Th70+tw0UKMg2NAuij6W6EOegS/4lLHQsE7Vfv0TpwF+XrR8TkxlmRc4WMkZU+hFHbOh6Hba/IS5PNTC1oVPSyJbJLQbXRC6mqVJUzX7UFZlBqz/vKJqRkaAu8Ugly7qwoY/VK2e2+tl/B8lig= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=L9/V6OAd; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="L9/V6OAd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1790603989; x=1822139989; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=oK3jZxxDr0BnpPbmFCjbTWLPyFqxlCPZlscEIjM9pLE=; b=L9/V6OAdRpBgIHePdL1yvqJHwBC1ciijAs3Ampwh8qlkofok3OHt9GzS ZSarOR2zOnCXrlmq5cTgbCThUTH3HyLgiqkoVZ5oksc07nEGH+GFmQVvz 141uWvBtDw7DQh8mLiKRqAFyuFSu8yyNDZfP7uJ36vuHzXzSnPz3OfN+V 7bqc67qQh9E76Q70HoJ62Y/t7JwPu5mHn6I29qtyWUftNEYjNGBly0Ogg eamw2UE+roqgv9K7CwOIBuxYEJ0IPyfhCrbRqF3TXFn7PF53TMP6ZeYs+ 8YiG+zG9Ljv+JdvjDRpKhAaVXiwS9KlsbQU8cMKidlEvg3YvER+durc/M A==; X-CSE-ConnectionGUID: g8d3cCE6SFypsKZJOJrp5g== X-CSE-MsgGUID: HN8kgLkCSXyQ5zkto8qrHw== X-IronPort-AV: E=McAfee;i="6800,10657,11919"; a="90068800" X-IronPort-AV: E=Sophos;i="6.27,128,1787036400"; d="scan'208";a="90068800" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2026 06:59:49 -0700 X-CSE-ConnectionGUID: NEJqQGimT4C8rbhoiu06Zg== X-CSE-MsgGUID: rI73WS/oRnSCECNXKNG0Fg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,128,1787036400"; d="scan'208";a="301354197" Received: from black.igk.intel.com ([10.91.253.5]) by fmviesa002.fm.intel.com with ESMTP; 28 Sep 2026 06:59:47 -0700 Received: by black.igk.intel.com (Postfix, from userid 1008) id C369A99; Mon, 28 Sep 2026 15:59:46 +0200 (CEST) Date: Mon, 28 Sep 2026 15:59:46 +0200 From: Heikki Krogerus To: Carlo D'Ambrosio Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [BUG] usb: typec: ucsi: Acer Aspire 16 AI reports connector 2 while num_connectors=1 Message-ID: References: <18c22d05-af53-4d94-b6ff-91441adc65c2@gmail.com> <48e56ed1-d8ef-4d26-8c18-9bb0fa2e5a7a@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48e56ed1-d8ef-4d26-8c18-9bb0fa2e5a7a@gmail.com> On Sun, Sep 27, 2026 at 09:04:09PM +0200, Carlo D'Ambrosio wrote: > Hello, > > I did one additional A/B trace which seems to explain why the notification > storm persists. > > Starting from a clean Windows -> Fedora boot, I traced > |ucsi_notify_common()|and |ucsi_acpi_async_control()|and connected the > charger to the lower USB-C port, which behaves normally. > > The first event was: > > |NOTIFY CCI=0x20000002 connector=1 num_connectors=1 CONTROL > command=0x0000000000010012| > > |0x12|is |UCSI_GET_CONNECTOR_STATUS|, with connector 1 encoded in the > command. > > This was followed by: > > |NOTIFY CCI=0x80000900 CONTROL command=0x0000000000030004 NOTIFY > CCI=0x20000000| > > From |ucsi.h|, |0x04|is |UCSI_ACK_CC_CI|, bit 16 is > |UCSI_ACK_CONNECTOR_CHANGE|, and bit 17 is |UCSI_ACK_COMMAND_COMPLETE|. > Therefore |0x00030004|is: > > |ACK_CC_CI | ACK_CONNECTOR_CHANGE | ACK_COMMAND_COMPLETE| > > So for the valid connector-1 notification, Linux performs the expected > |GET_CONNECTOR_STATUS(1)|and subsequently acknowledges the connector change. > > In contrast, when the upper USB-C port triggers the problem, the trace is > only: > > |NOTIFY CCI=0x20000004 connector=2 num_connectors=1 NOTIFY CCI=0x20000004 > connector=2 num_connectors=1 ...| > > approximately every 570 ms, with *no calls at all to > |ucsi_acpi_async_control()|*during the loop. > > This matches |ucsi_notify_common()|: because connector 2 is greater than > |ucsi->cap.num_connectors|(1), |ucsi_connector_change()|is not called, so > the normal connector-change handling/acknowledgement path is never entered. > > Also, to correct an interpretation I was considering earlier: |0x20000004|is > *ACK_COMPLETE + connector 2*, not ERROR + connector 2 > (|UCSI_CCI_ACK_COMPLETE|is bit 29; |UCSI_CCI_ERROR|is bit 30). > > This seems to leave two separate questions: > > 1. Why does the PPM expose |num_connectors=1|via GET_CAPABILITY while > the upper physical USB-C port generates connector-change indicator 2? > 2. Independently, should Linux do anything to acknowledge/drop an > out-of-range connector-change notification to prevent a persistent > notification storm, or is the current behavior intentional? Please report the issue to Acer if you have not yet done so. This is an obvious FW/PPM issue. Thanks, -- heikki