From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 0C6824C77D7; Wed, 21 Jan 2026 15:19:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769008763; cv=none; b=RwWWdLU+Ei5Ae2Alk3Gu3jhAa4jO8erIYTtqLhAQ7dtdlmBiS6kuRDNr/GWT8Te/kIco63djseQV8xjJfxMXkNBymSKoQqdEvbU8x3R7IML/miJn2wxJ8OBhv3wwIOI9OLmmJttCH8ak4QF4gcmd16zFUqQfcQkLtG5AN+wvAf0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769008763; c=relaxed/simple; bh=1+YSusSEMkMAiteRU+8FWU3WXTOqPIoC9SA8+ckckPE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aOmyo66PO7krr3eIgy7YjLrhlJeHBMgV2UHSO34sGqTK5FwEqIM+VzN54LRyCpramBrZTJWsRxDV/u6VyAy6a8hTYfXKhdn6bmjN7xsFrrYWjuxJOBOnvLZGQr/rpU3MH7G1PWQxXgPY8oyCJi7AO+RogHyqQfHxg6KMDxn7J04= 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=db1fv9Sv; arc=none smtp.client-ip=198.175.65.14 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="db1fv9Sv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769008761; x=1800544761; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=1+YSusSEMkMAiteRU+8FWU3WXTOqPIoC9SA8+ckckPE=; b=db1fv9SvDRze8zmO6vEMUtfatje6yVBeVhu58uZ7+bgAOgEx3T9OuV/E DKgVPpw65pCVlUZOy61TeEkwvyf3O7G50qAwrGfhlysK2kJKW6CE/Xj02 b4F/Io4UIkEp9M9JZxwdYFBxQvFVplQHfCMfEKpFpdrvZel7hGUaP7ABr oCqep96B3TJtBtWHqXYvlvgy+FVNsal5f0jTLr+ABxLSzJHvwHBwZ4DoG 8UhUSYeKr3KPDfSkPe3EgmaZdQg4cpAFIWCIzkzATkRfL6aNK54PwvSbo 95igVpOnYiVFansa8qNTbKe+h6O3x7hYX4TvK+WaKmrdtszAe6rdFXmMI g==; X-CSE-ConnectionGUID: lCqfYnuvSzaC705L0bxUGA== X-CSE-MsgGUID: w2pvlh73Tp+G725++hXlmw== X-IronPort-AV: E=McAfee;i="6800,10657,11678"; a="74090987" X-IronPort-AV: E=Sophos;i="6.21,242,1763452800"; d="scan'208";a="74090987" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jan 2026 07:19:20 -0800 X-CSE-ConnectionGUID: g0jgJXSxRPGgyjpSQGDc/w== X-CSE-MsgGUID: pH4uvPkMSuK1JGNxQzZGQQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,242,1763452800"; d="scan'208";a="244047150" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.245.73]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jan 2026 07:19:20 -0800 Date: Wed, 21 Jan 2026 17:19:17 +0200 From: Andy Shevchenko To: Mika Westerberg Cc: correctmost , 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: <20260121135803.GM2275908@black.igk.intel.com> <20260121150256.GN2275908@black.igk.intel.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: <20260121150256.GN2275908@black.igk.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Wed, Jan 21, 2026 at 04:02:56PM +0100, Mika Westerberg wrote: > On Wed, Jan 21, 2026 at 04:54:43PM +0200, Andy Shevchenko wrote: > > > My understanding is that some models touchpad does not work if the idma64 > > > driver is loaded but they do work if it is not. Also there is some sort of > > > interrupt flood coming from somewhere? > > > > > > When idma64 is not present the toucpad works flawlessly? > > > > On *old* kernels where idma64 blindly acknowledges all the interrupts. > > Fixed idma64 doesn't affect the IRQ storm because it's just a given > > fact on these laptops. > > > > > Does it works in Windows? > > > > > > I mean if it works in Windows and we also know it works in Linux without > > > idma64 then we can go with some sort of quirk (or better yet figure out > > > what is going on) to keep users touchpads working. I think this is much > > > better option than asking BIOS update from vendor which there is close to > > > zero possibility to happen in reality. > > > > What kind of a quirk? Just to create a module that will request the same IRQ > > and always acknowledges it? Sounds to me like a heavily papering over solution > > TBH. (Yes, I assume it may be used only on DMI based enumeration only on the > > affected models, but still...) > > Well I mean if touchpads actually worked prior this idma64 commit and now > they don't isn't that a regression? I don't think so, because commit did the right thing and just revealed an issue that was rather hidden. Reverting is not an option. > After that one commit touchpads don't > work anymore. I would much rather make sure users devices keep functional > even if it turns out to be hack of some sort. It's one of the ugliest hacks I ever seen. I really don't want to go this way. In any case, the problem is with interrupts coming from I²C controller. You can consider adding that hack into there which sounds at least much better place than idma64.c which has nothing to do with all this. > For example could be blacklist idma64? Does that help? No, it won't. > Yes the interrupt flood still happens but if that does not affect the > toucpad then that's still better than non-functional touchpad IMO. So, the only "best" option I see is to add a quirk module (somewhere in PDx86 area) that just registers an interrupt handler to acknowledge it. Very weird. -- With Best Regards, Andy Shevchenko