From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 E6B4C5D904; Wed, 6 Mar 2024 15:04:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709737485; cv=none; b=k85yBnU/2Vuzs8xTdOlPY9ZIEijQU/XWZZqR7iSfD1ZixMr+ej0b7PVgekP+NNknx8C70EDmy/b9TYZEJEtl/qntpVpqyTVeZvSkq+hx+lxg4NyN+VqDh5cooq51QrhRP8WlE7JO5yo2Hf/NYNdMicaDErNXdW4D66i+7dLED+k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709737485; c=relaxed/simple; bh=s0cP/vdeTBfqUMpPi1K2dMYOFXlNATU+OscAfsIgh9Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KVBauO5XqTUwpANohxNPl7/09XovzAhJMj0K2kGifo8OtTMe40QnqVPH/B2X0nVFd+V2gbcqOugnRO36pOIxUQyquikhdmX7p2jigb4MUzFyJv+M7JonEdmkA020jFqAOqAUFNMZv0kKEGnUnWXy5r6V2cqurgeP7+wxj+i8LUY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=ZSFZ7s8Y; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ZSFZ7s8Y" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bIU+Y5tx9f1r7LHMtxJaaNjMHc4LWtkAUlFKv4XMp0s=; b=ZSFZ7s8YIDIt3b0Xse+j2mtEhj YBv9PmhQb2Sr+mtg/nLN85fQCd08SSYbxHLzctr+hn9NTjtJpKHlOZO3UoZkorkMF8JxiHBn35N+K kcCo51zZYbX228avPHZxiQzHGn5kj1WL7jgXHzPJKtzaA4Q33z8OYpDxSbyTw0jB/VCXk50bHviC7 l91UxkVIUBnshpCIvi6dqC6HKYm9rVf/uMuASQlVOPcBPM7dYi7Q/UN+NcF2mwUXFqGB4zFTD+drp 9/QveY/6yGnml+UULDxNINgBZVmuKJ7gj7tBN5HHWorUcTW2fosCnVaES8QpEqpwQc/15FN9l/RS3 CX7hQ42g==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rhsow-00000000hHr-35do; Wed, 06 Mar 2024 15:04:38 +0000 Date: Wed, 6 Mar 2024 07:04:38 -0800 From: Christoph Hellwig To: Andreas Larsson Cc: Arnd Bergmann , Sam Ravnborg , "Maciej W. Rozycki" , sparclinux@vger.kernel.org, Randy Dunlap , Miquel Raynal , linux-parport@lists.infradead.org, "David S . Miller" , linux-kernel@vger.kernel.org, Takashi Iwai , iommu@lists.linux.dev, linux-kbuild@vger.kernel.org, Masahiro Yamada Subject: Re: [PATCH v2 4/7] sparc32: Do not select ZONE_DMA Message-ID: References: <20240224-sam-fix-sparc32-all-builds-v2-0-1f186603c5c4@ravnborg.org> <20240224-sam-fix-sparc32-all-builds-v2-4-1f186603c5c4@ravnborg.org> <8d5780f5-1047-48d7-a9c9-09b95c7b5604@gaisler.com> <5648dca0-4853-4dfb-91cf-282a656beb1e@app.fastmail.com> 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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Mar 06, 2024 at 03:19:52PM +0100, Andreas Larsson wrote: > > I think that is the correct thing to do then: the only > > drivers that I see with this dependency are PCI sound cards > > that apparently rely on DMA to the 16MB ISA range, which is > > not provided by sparc. > > The ZONE_DMA dependency does not seem related to ISA per se. Commit > 80ab8eae70e5 ("ALSA: Enable CONFIG_ZONE_DMA for smaller PCI DMA masks") > that started to introduce it did were about ensuring 32-bit masks. Yikes! That commit is just unbelievable buggy. CONFIG_ZONE_DMA is only for architetures to select, not drivers. A driver randomly enabling such an arch zone is just crazy. I've been wondering for a while if we need some Kconfig magic so that certain symbols can only be select from arch/* and not elsewhere to prevent this (we had a few other similar cases like DMA_MAP_OPS).