From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (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 15383456E1E for ; Wed, 5 Aug 2026 12:11:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785931907; cv=none; b=WXRhIXbE9XXflVB3EsQgrVql+zY10PimgJAc8STMKAhVFZvukylU+Kl4teop6J+pJV0S62IKoNiy0IRyrDD/4p2qOVxGNnNfRKszM4nqSOkUBbE5R9xrgevf/TxC6n4y2y6Oyq1Vi5vVJorL8b2YNxH4zacazbXxrbQPogHSf8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785931907; c=relaxed/simple; bh=k+Mm4uqcNyM1cwOW56sVAQ88X8umlqFjOdhpQTW2970=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=N+p2KC5PUG1wjSiotN7zCSCaFvf1p3HrYQSdMG79y0Hm5nmwhHdWwILFR7F1K7a8uxVcIpXHvMz21ngTPeo8AOhB5o2epqy1rRU4c/78l7PGi3hQnmqwq09DehLskolxoKmnY1qrS/j/RgQ4ssI994+XVafVkpUSGDgzPvcUDM0= 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=FjQ80wIN; arc=none smtp.client-ip=198.175.65.16 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="FjQ80wIN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785931906; x=1817467906; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=k+Mm4uqcNyM1cwOW56sVAQ88X8umlqFjOdhpQTW2970=; b=FjQ80wIN16EK++SJCPIKrnuaB67MeX0CapAYubrEYgb+PL/VnrZ3NMoY C07T7Ax2s5RpbGuzqtqUwuod967XryrI/Tbt8E3nU8VPzY+ib4fm5dRd1 R6qQLruYcOgl6/iHySNs8GHokT7GLFHM49uwjHTGHnfBCtkrnmlS0Opzz b5YbjWwl/uJ2C1SB1ZvQCrBuX7u8YhGMuTSYJJ+8YZ573lzRJdvr6TOTw 7s7nfxgsStkRtM37aEEFimOD2ocHV2xwgC7GxGKrpIuaqbTg0/L9e+R+n XtwvmlRsw8QXeVNiUWLdqXHzCXbIqMvVIEvkxrOh+zNKYHoyAik2da0ZN A==; X-CSE-ConnectionGUID: n/o2Sd3oQIepxfnovNk0mQ== X-CSE-MsgGUID: ca4lPleOToigJ/f9T3xMHQ== X-IronPort-AV: E=McAfee;i="6800,10657,11865"; a="86705231" X-IronPort-AV: E=Sophos;i="6.25,206,1779174000"; d="scan'208";a="86705231" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2026 05:11:46 -0700 X-CSE-ConnectionGUID: zEd44JW4QPWC+1cLODkCWw== X-CSE-MsgGUID: qQ7ingHfR36UKSEgtHn0wA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,206,1779174000"; d="scan'208";a="286450233" Received: from black.igk.intel.com ([10.91.253.5]) by fmviesa001.fm.intel.com with ESMTP; 05 Aug 2026 05:11:45 -0700 Received: by black.igk.intel.com (Postfix, from userid 1008) id 9155899; Wed, 05 Aug 2026 14:11:43 +0200 (CEST) Date: Wed, 5 Aug 2026 14:11:43 +0200 From: Heikki Krogerus To: Jacob Riff Cc: linux-usb@vger.kernel.org Subject: Re: ucsi_acpi: intermittent "PPM init failed" at boot is never retried, Type-C event handling stays dead for the session Message-ID: References: Precedence: bulk X-Mailing-List: linux-usb@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: On Sat, Jul 25, 2026 at 02:31:53PM -0700, Jacob Riff wrote: > Hi, > > On a Lenovo ThinkPad X1 Carbon Gen 14 (21V7CTO1WW, Panther Lake), UCSI > initialization intermittently fails at boot, and because the failure is > never retried, no typec ports are registered for the rest of the > session. Most visible consequence: after unplugging and replugging the > USB-C charger (a PD monitor), the machine silently never resumes > charging. Notably, DisplayPort alt mode on the same port continues to > work across replugs in this state, and charging does work if the > charger was already attached at boot (EC autonomous) - it is > specifically resumption of charging after a replug that is lost, which > makes the failure easy to miss until the battery is unexpectedly > drained. > > Failure rate: 5 of 8 boots on one day of testing. Reproduced on two > firmware versions including the latest (BIOS N4OET49W/1.12 and > N4OET51W/1.14, EC 1.09 and 1.10). No clear correlation with whether > anything is attached at boot: two boots one minute apart with the same > setup split ok/fail. > > Kernel: 7.1.4 (Arch Linux, unpatched in this area) > > Two failure flavors seen: > > ucsi_acpi USBC000:00: error -ENODEV: PPM init failed > > and: > > ucsi_acpi USBC000:00: possible UCSI driver bug 2 > ucsi_acpi USBC000:00: error -EINVAL: PPM init failed > > Both appear ~1s after the typec ports bind. On failed boots > /sys/class/typec/ stays empty. > > The part that suggests a driver-side improvement: recovery is trivial. > Reloading the module seconds later has succeeded on every attempt so > far (double digits by now): > > modprobe -r ucsi_acpi && sleep 2 && modprobe ucsi_acpi > > after which connectors register and charging renegotiates immediately, > no replug needed. > > ucsi_init_work() currently only requeues the init work for > -EPROBE_DEFER (up to UCSI_ROLE_SWITCH_WAIT_COUNT). Given that an > immediate retry reliably succeeds here, would it be reasonable to also > retry a few times on other errors (-ENODEV/-EINVAL) before giving up? > The PPM on these machines appears to simply not be ready to answer > during a window around when init runs. > > Possibly related prior reports of Lenovo PPMs being slow/unready at > init: the "usb: typec: ucsi: increase timeout for PPM reset operations" > RFC (Feb 2025) and Ubuntu bug #2054928 (ThinkPad E490, -ENODEV). > > Happy to test patches on this hardware. I'm sorry to keep you waiting. I'm just letting you know that this issue is in my queue, but right now I don't have time. I will try to take a closer look at this later this month. Thanks, -- heikki