From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 F3719387588; Tue, 30 Jun 2026 16:48:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782838087; cv=none; b=U4Y8x7ngKp51L0Y3BdUaukVr/73MzaW4qoZDmlPhAe+zR7MknCUCyCy+Qov5FtusQ6Q85ybDICVrO9oJXefmKAfPv8RZo7CTaCtq40ljHhgssZvXnIYkIIQhY3dsQvy82Z/9/n013amTm+8a3FGnTL2eGOcuiGhChxbw8gZiNg8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782838087; c=relaxed/simple; bh=pjBPF2DGIK1jzhKqPI/vUBhcxsMj5K5QCHSwZ3gNkO4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bJKU31utjFX+djyDrObgqjf6ShmhBWiGSRZiK7LtYLgUaZRWTvmWcgYxc4nhNxWN5IJQg+TUiDXO8nzVXzU73Ba9N7x173g+EvJLqLVr13nGA+P+ncjAulybk95cmMXPpVuEgM+j9KY8iC1Ths0u20O/x6a20Es2mjmpwPEGRis= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z54EhXZ5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z54EhXZ5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 662971F000E9; Tue, 30 Jun 2026 16:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782838085; bh=aQME56hxrnfMv8y1HuSYOXEeBCbRKzTFUcscWXVXKE0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Z54EhXZ5X2YgK7JbcAbTLsK/UJhjf475ABh03MFW5BJ4o2CiOCeRW71iitG7DPpql 0roMyl2c0aHBngl7wl3TfGKzz55Oa6quU3Hk8ekE2iyOk0SQ5h2+0W9ChAt7vNHraU Y5RR7Tp3IABI2RUG6mNk0P5/m+KH7494xQF93vNtgI4DoIMb1+kt2jiLsLCwEnjMnY XQ2jP7+B3rdWTUjHBbaxVJ46gWhywnSQDUgs3wHIkCeexgcg0mWsVqXPe0z7X/hJOX s0N6Cyg4QD6fmrw/y/nKI7n0j8YxgBIQjh3DbffPOra36Sx7J0AXPSa6fwKclzoH+Z OyI3awpgu0PSw== Date: Tue, 30 Jun 2026 11:48:04 -0500 From: Rob Herring To: Daniel Palmer Cc: saravanak@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] of/address: Drop ISA parts when !CONFIG_ISA Message-ID: <20260630164804.GA3920230-robh@kernel.org> References: <20260626171906.476688-1-daniel@thingy.jp> Precedence: bulk X-Mailing-List: linux-kernel@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 Sun, Jun 28, 2026 at 02:44:51PM +0900, Daniel Palmer wrote: > Hi Daniel, (Replying to myself..) > > On Sat, 27 Jun 2026 at 02:19, Daniel Palmer wrote: > > > > The PCI parts are already wrapped in #ifdef CONFIG_PCI > > so it seems sensible to add #ifdef CONFIG_ISA around the ISA > > parts. > > > > This reduces the code/data size a bit on configs with !CONFIG_ISA. > > > > Signed-off-by: Daniel Palmer > > --- > > > > Sorry for the spam, somehow I botched sending a patch.. > > > > I thought about making this RFC as I'm a bit unsure if machines > > that need this ISA stuff actually select CONFIG_ISA or not. > > So sashiko worked out what is going on here. A few machines have > things connected via an LPC bus that is derived from ISA and needs the > code to parse those nodes but those machines don't select CONFIG_ISA. > There seem to be ~15 devicetrees in total that actually need it (1 in > x86, 1 in arm64, a few in mips/loongson for loongson machines, and > then a few in ppc). > > I made a series that adds CONFIG_OF_ISA to enable this code, selects > it in the places that needs it, and then does the original part of > disabling the code if not needed. I will wait a bit before sending. > The reason to do this is I am using devicetree to boot a machine with > 4MB of RAM and a 7MHz CPU. Removing dead code/data like this helps. I tend to not want more CONFIG_OF_foo options, but okay I guess. Alternatively, maybe CONFIG_ISA should just be enabled with these drivers. Doesn't really look like there's actually much or any code for CONFIG_ISA. The biggest issue might be the option doesn't exist on arm64. Rob