From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 4B92327F4F5; Mon, 12 Jan 2026 14:35:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768228510; cv=none; b=NDTmFS1l/PKfW6JTyqI4P2F+cMXUEtbFnhHAN+sPhEMoW4+S780iaJtxe/VEl+KUIRUBU3ikB9Ugliu7XMFbZHEfQaACdRXZCRsNUWrhRBuBKY9ENowne396SXr7V4JT8SgSIhST6FeqAMUb35AJyhaFe20N8N1hIehlu2fecfA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768228510; c=relaxed/simple; bh=CcKwT1f6+g65+WAdcan+bOmjmZsRnEsccq0m+MJx7sg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i/8XFlD1DxoqkvATvsSd/IaFbdZ49aOeuE/e/4NDf0hEAO8Ip4UltIUbtIEbidouorImA5DR7VxWkoAmMbn9mhNivVg+EQZEGH50Q1gNobDuj4JA92Yr/ORnKUt3KmAHdsAObXWxi98DYBmdSuaRiXyNKD9LxYnNYl/HkOj2BDQ= 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=f3GAvpEG; arc=none smtp.client-ip=192.198.163.11 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="f3GAvpEG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768228509; x=1799764509; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=CcKwT1f6+g65+WAdcan+bOmjmZsRnEsccq0m+MJx7sg=; b=f3GAvpEGO53XIaiyx96fxf3BPPG44maIGQebHWlWOnKTLF9ASC1U2h6k j82EXntFhoOhRmIwT8OW5KieXGCl5m84jyuWszmeOs8iP/H63+S+exk73 +YaeIFgEwnHUHH/CsjQnjYKGnCFgfWYy8yQ0/TlMz+trj2W9yE0xJuDD6 uQZPzjTcJ0kQrtoF1RZMKOb+bOPGX/IImQmox7rpgcXUnRgUWA1mO9i7m uFGGlSuO7OvTEQdLezjii6Qsw1gJn9OycUch979lxhEHhkG+Z4Bw6IhOi FjxHQR5if4ekjVQptuC2yQ/4J+fLGC8vUZTyHmBvfXFZ6Wwy1apNMeV1Y Q==; X-CSE-ConnectionGUID: TKSCnUh0S2O1C0kSdcmlCw== X-CSE-MsgGUID: lyfL8nkGS5yfV92nrQ8d9w== X-IronPort-AV: E=McAfee;i="6800,10657,11669"; a="80138095" X-IronPort-AV: E=Sophos;i="6.21,221,1763452800"; d="scan'208";a="80138095" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 06:35:08 -0800 X-CSE-ConnectionGUID: PPHZO89MQD6AJhca5prrwA== X-CSE-MsgGUID: 02R4gdQERmeLuuKV6vgePw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,221,1763452800"; d="scan'208";a="204009002" Received: from dhhellew-desk2.ger.corp.intel.com (HELO localhost) ([10.245.245.37]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 06:35:07 -0800 Date: Mon, 12 Jan 2026 16:35:05 +0200 From: Andy Shevchenko To: correctmost Cc: dmaengine@vger.kernel.org, regressions@lists.linux.dev, vkoul@kernel.org, linux-i2c@vger.kernel.org Subject: Re: [REGRESSION][BISECTED] Lenovo IdeaPad touchpad does not work when idma64 is present in initramfs Message-ID: References: <51388859-bf5f-484c-9937-8f6883393b4d@app.fastmail.com> Precedence: bulk X-Mailing-List: dmaengine@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <51388859-bf5f-484c-9937-8f6883393b4d@app.fastmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Dec 16, 2025 at 12:57:10PM -0500, correctmost wrote: > The following commit No, it's false positive. The reality is that something else is going on there on this and other similar laptops. > causes my Lenovo IdeaPad touchpad not to work when > kernel/drivers/dma/idma64.ko.zst is present in the initramfs image: > > #regzbot introduced: 9140ce47872bfd89fca888c2f992faa51d20c2bc > > "idma64: Don't try to serve interrupts when device is powered off" So, the touchpad is an I²C device, which is connected to an Intel SoC. The I²C host controller is Synopsys DesignWare. On Intel SoCs the above mentioned IP is generated with private DMA engine, that's called Intel iDMA 64-bit. Basically it's two devices under a single PCI hood. The problem here is that when PCI device is in D3, both devices are powered off, but something sends an interrupt and it's not recognized being the one, send by a device (touchpad). There is one of the following potential issues (or their combinations): - the I²C host controller hardware got off too early - the line is shared with something else that generates interrupt storm - the BIOS does weird (wrong) things at a boot time, like not properly shutting down and disabling interrupt sources; also may have wrong pin control settings - the touchpad is operating on higher frequency like 400kHz (because BIOS told to use that one instead of 100kHz) than the HW is designed for and hence unreliable with all possible side effects - the touchpad firmware behaves wrongly on some sequences (see also note about the bus speed above), try to upgrade touchpad FW With my experience with the case of the above mentioned commit that it may be BIOS thingy. Also consider the bus speed, there are quirks in the kernel for that. > Here are the related logs: > > --- > > irq 27: nobody cared (try booting with the "irqpoll" option) Almost all below is not so interesting. ... > handlers: > [<00000000104a7621>] idma64_irq [idma64] > [<00000000bd8d08e9>] i2c_dw_isr > Disabling IRQ #27 Yes, this line at least shared between those two and might be more. ... > i2c_designware i2c_designware.0: controller timed out > hid (null): reading report descriptor failed > i2c_hid_acpi i2c-ELAN06FA:00: can't add hid device: -110 > i2c_hid_acpi i2c-ELAN06FA:00: probe with driver i2c_hid_acpi failed with error -110 Yes, sounds familiar with the speed settings. Try to down it to 100kHz in case it's confirmed to be 400kHz. > --- > > Hardware info: > - Lenovo 16" IdeaPad Slim 5 - 16IRU9 > - Hardware name: LENOVO 83FW/LNVNB161216, BIOS PFCN14WW 09/20/2024 > - ELAN06FA:00 04F3:327E Touchpad > > Steps to reproduce: > - Cold boot the laptop on Arch Linux > > The bug is still present with the 6.19.0-rc1-1-git kernel. > > The bisected commit is from March 2024, but I only recently noticed the issue > because the initramfs images on Arch Linux now include these additional > drivers (as of November 2025): > - kernel/drivers/dma/idma64.ko.zst > - kernel/drivers/mfd/intel-lpss-pci.ko.zst > - kernel/drivers/mfd/intel-lpss.ko.zst > > Two other users have reported the issue on the Arch Linux and CachyOS forums, Any pointers to that thread, please? > so I don't think this is a hardware issue with my individual laptop. I don't know how this conclusion is came here. You mean HW as laptop model? But are the involved components the same (I²C host controller + touchpad)? -- With Best Regards, Andy Shevchenko