From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 2A3153195E8; Fri, 16 Jan 2026 10:35:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768559739; cv=none; b=liuGV5ZOq5eskoFeOeciXgdbYHkp9obOhlwYkfm+alN61cGNFAy1Rji1wQsSWXNIPb2IY+djOw/XqqyoCujmCBcxLDqyyzC1Q15QNtmiDXSwtMb/MrqrO98J5V3LJmLzhtSe162mPY/oJb+eZTmyteLcXY8sTlJoJIrgKGQxqA4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768559739; c=relaxed/simple; bh=aiIGlsJXL0tDmzaEhpskji5W6TU6kJO+JTTWJog4LWk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NG1X2HMU4UJOL9xwVwOqB9nnnoKREQvbmVwYvAa4c+NhSoPb4Sg53DU+OR0IlRLkyqnk8U6XRRQ90WiQNiThTIBPWJyNdcj3+BMO38/98b1s16/NG5qw2TmJxrK/mdGWo1grS6ExjwSDv5DNMWg6jsrd+GAo86fcHkqv2E4akqg= 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=ib2Shv4r; arc=none smtp.client-ip=192.198.163.17 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="ib2Shv4r" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768559737; x=1800095737; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=aiIGlsJXL0tDmzaEhpskji5W6TU6kJO+JTTWJog4LWk=; b=ib2Shv4rNu9pyPvQB0e6gxAysxLTiUFt7WU2y2362xVFOWQThjynAapl mNXsF5eKB3I88UzHczn1OnG82sg7s2jv2M0MqJggw41sJF/60GoXcfGNN CCQJePFnNsXT1ZOAvN3QfSMZM+WRCR2uuKJ2hhLJeawd+B2uowg3DevJl WtPrTtjVfPCZiarmpxSt+SAVeYl+p7slha6rvKPWU29kqErPGfL4TTrCf j1JWzA6qtQ6KlAmpotqLRlEirY0HRdAuqT8IJrOoYB/DFRw3I0JhP1sG0 rlpEcTEDJySuizlzaJMul5xqHZNnsqVtZmzwIHABBsETP+2y6CPl+BR8S A==; X-CSE-ConnectionGUID: qAjVUn6+QGSYtq01PONLtA== X-CSE-MsgGUID: 6k2Q3mFWTIymC7PhNL/0IA== X-IronPort-AV: E=McAfee;i="6800,10657,11672"; a="69776855" X-IronPort-AV: E=Sophos;i="6.21,230,1763452800"; d="scan'208";a="69776855" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2026 02:35:36 -0800 X-CSE-ConnectionGUID: qNkMSGQDR+WVpxKlQ4UVrg== X-CSE-MsgGUID: l3ELfngdSqy6wtCjo2smzQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,230,1763452800"; d="scan'208";a="235901137" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.245.99]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2026 02:35:34 -0800 Date: Fri, 16 Jan 2026 12:35:31 +0200 From: Andy Shevchenko To: correctmost Cc: dmaengine@vger.kernel.org, regressions@lists.linux.dev, vkoul@kernel.org, linux-i2c@vger.kernel.org, mika.westerberg@linux.intel.com 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> <69f5dea3-17b0-4d3a-9de7-eb54f8f0f5cd@app.fastmail.com> Precedence: bulk X-Mailing-List: linux-i2c@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: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Fri, Jan 16, 2026 at 12:03:12PM +0200, Andy Shevchenko wrote: > On Thu, Jan 15, 2026 at 05:50:36PM -0500, correctmost wrote: > > On Mon, Jan 12, 2026, at 9:35 AM, Andy Shevchenko wrote: > > > 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. > > > > Thank you for the detailed notes. I will see if I can update my BIOS and > > experiment with different quirks values, though I won't be able to do that > > until late next week. > > You're welcome! > > > >> 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. > > > > > >> --- > > > > > > Any pointers to that thread, please? > > > > The following threads have users who were able to restore touchpad > > functionality by undoing the idma64 change in initramfs: > > Yes, = "they have hidden the existing problem". No value in that, sorry. > What is the exact link that refer to the thread you previously mentioned? > > ... > > > Lastly, I saw another bug report that mentions the "probe with driver > > i2c_hid_acpi failed with error -110" error. It seems to state that the error > > only occurs when a power cable is connected during boot: > > > > - https://bugzilla.altlinux.org/57094 > > - Huawei Matebook D15 BOD-WXX9-PCB-B4 > > - i2c-GXTP7863:00 > > > > >> 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)? > > > > Sorry for the confusion. I meant the individual machine in my possession and > > not the laptop model as a whole. > > Yeah, something here is common and I can't say for sure this all about Synaptic > touchpads... So, what I think I need to understand this more is the following (all information should be gathered under root user) for working and non-working cases: - `cat /proc/interrupts` - `dmesg` # with `initcall_debug ignore_loglevel` added to the kernel command line - `cat /sys/kernel/debug/pinctrl/.../pins` # ... should be something like INTC1234:00 And just once these: - `acpidump -o tables.dat` # the tables.dat file - `grep -H 15 /sys/bus/acpi/devices/*/status` - `lspci -nk -vv` -- With Best Regards, Andy Shevchenko