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 A47E23C1D5E; Mon, 31 Aug 2026 07:28:09 +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=1788161291; cv=none; b=NHQSEpmN3n8J41KcEF7fK6MEmC0YXK1hJDSSMY+JhoFVgnY8G/vg/U5xA1nISb4VdGyUTUhAc8I+OkFB2Qojlra0T90J6XOza5S37NYb/7fhRPpp+B5oQEdU4AqkJNlyo20CmTfywt/ZkqdNug0bYYEzQX4GhUXypT0J8pi/5x8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788161291; c=relaxed/simple; bh=FXtZHMaUyuz6tloPARhW1tSsICenfu1kk99C0DJp/Sc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pP4oEYz5TPiCVfrf2BuJiAf/+WDe88C6zuApDrn+iLZiN+JBI+H5akzUO6i7j1dsDVGQ0+NSm421I7yTpt6w++fGeGY4gbPqFDSXIj20zQ1Qo+3LxHKAftQZOtBnwujIHaGMFsz+docGfepAkdID/ddvSO/xs95yApAaPQerXFY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WhTdb0yy; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WhTdb0yy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788161290; x=1819697290; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=FXtZHMaUyuz6tloPARhW1tSsICenfu1kk99C0DJp/Sc=; b=WhTdb0yyrFf6b/BMVpAuQXlbL9rP27wPq6Um4s/2zD6mWNJbLr+3YNsl LjMCNaTasFlrcrriA1Ef2HhFzPPrZldFKSXAymH6oYvmWg3syvB9F6xhl 2oxYSOEbtsNOSz/0sG4XjSqiElhYnKydiGtvf0rU6nuqEDalWl3nLwFgN bMTTzoRy6V6FUw5jkAW4AN1zA58V899aGiAvpVsZzDiFEW1VKVnyO1IcQ DRug0rE/f/aBuihehFuAYdyQ0xremMgXzRAE0AzBDVhYJXpYRkRBACL2Z dzYrvMnvJ+C/2eQTm7DGL1kPXK9W0NPW1I3yXF5ekhYjC0e1K4am2597q g==; X-CSE-ConnectionGUID: NBcf8krJRrmfGQ/XbVOuRw== X-CSE-MsgGUID: c1TRNln1Q6yvSmU0iFTjPg== X-IronPort-AV: E=McAfee;i="6800,10657,11891"; a="88322656" X-IronPort-AV: E=Sophos;i="6.25,252,1779174000"; d="scan'208";a="88322656" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2026 00:28:09 -0700 X-CSE-ConnectionGUID: pXYTBenFQ0yxxjo+9nO0xA== X-CSE-MsgGUID: sFv3dv+eTLm3/gTPVzkoMQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,252,1779174000"; d="scan'208";a="273989107" Received: from fpallare-mobl4.ger.corp.intel.com (HELO localhost) ([10.245.244.21]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2026 00:28:07 -0700 Date: Mon, 31 Aug 2026 10:28:04 +0300 From: Andy Shevchenko To: Peter Rosin Cc: Ahmad Byagowi , Andy Shevchenko , Andi Shyti , Jakub Kicinski , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 3/3] i2c: mux: Propagate software nodes to channel adapters Message-ID: References: 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 Mon, Aug 31, 2026 at 09:13:34AM +0200, Peter Rosin wrote: > Den Sat, Aug 29, 2026 at 10:10:40PM -0700, skrev Ahmad Byagowi: > > Peter, thanks for clarifying. > > > > The check is intentional. Without it, the generic traversal would also > > inspect ACPI firmware nodes and could match _DSD child nodes carrying > > a "reg" property, while the existing ACPI path below uses > > acpi_preset_companion() to associate the adapter by channel address. > > Yes, I got that. The question is if the precaution is really needed. > Are "reg" properties common in ACPI nodes? Nope, and we have documented how ACPI DSDT is supposed to be constructed for the I²C muxes, but as I answered there, it relies on a human (factor). > > I have not established that changing the ACPI lookup behavior is safe, > > and that change is not needed for software-node support. With the > > check retained, OF and software nodes use the generic lookup, while > > ACPI continues to use the existing acpi_preset_companion() path > > exclusively. > > Yes, I figured as much, which is why I directed the question at Andy. > > > That said, I will clarify this in the commit message for the next revision. > > I'd rather tweak the check to exclude ACPI (instead of including OF and > SW) with a code comment about why ACPI is excluded. That is, if it can > be determined that ACPI actually needs to be excluded. If it is hard to > get an answer to that question, I'm inclined to just attempt to not > exclude ACPI, and then be prepared to exclude ACPI in a follow-up if > there is any fallout. Agree (and also answered in the similar way earlier). -- With Best Regards, Andy Shevchenko