From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84F97C0650E for ; Wed, 3 Jul 2019 17:21:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FAD921881 for ; Wed, 3 Jul 2019 17:21:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="p54r3CaT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727242AbfGCRVm (ORCPT ); Wed, 3 Jul 2019 13:21:42 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48060 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727119AbfGCRVZ (ORCPT ); Wed, 3 Jul 2019 13:21:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=KLNpXUeBNjOGtXnDQ3qzX7M6wN19aQMGgVhJjQ1BSuc=; b=p54r3CaTxN1VjNO3vNGbNNXLB djZuP4fanPNsLlBqMzU5MoP+1WLXTYZva0j3m3P7OUtM3wERwG+ot3qGTaebOvLcOlZE0NaZzIL2D /HTFZdIBzKlwn1NFvQKlPE48i6NLNn5ZwqhLc804x/8rUCdrK0U+KhMah1s+XDe5M9w0MpvU4susf HjmAYtShG3Hd42th/Q8PDRRdMRwIQH7zILUpUh67kFTwPYTmmjHzvF5JLUV7gOAchy78zV/lHSv4x sJF1Mv54B5XJdRqqtIALihUynxzBVmmmmiJsl7TXUVScwRO2NcTplls5IExQYeZMS5sUhuWfEg2+L 0h3Q2PXug==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hiiwW-0007Al-2D; Wed, 03 Jul 2019 17:21:16 +0000 Date: Wed, 3 Jul 2019 10:21:16 -0700 From: Christoph Hellwig To: Maxime Chevallier Cc: Christoph Hellwig , Greg Kroah-Hartman , "Rafael J . Wysocki" , Rob Herring , Frank Rowand , Russell King , David Miller , brian.brooks@linaro.org, linux-kernel@vger.kernel.org, Antoine Tenart , thomas.petazzoni@bootlin.com, linux-arm-kernel@lists.infradead.org, nadavh@marvell.com, stefanc@marvell.com, Russell King Subject: Re: [PATCH] driver core: platform: Allow using a dedicated dma_mask for platform_device Message-ID: <20190703172115.GA22034@infradead.org> References: <20190628141550.22938-1-maxime.chevallier@bootlin.com> <20190628155946.GA16956@infradead.org> <20190701132340.21123dee@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190701132340.21123dee@bootlin.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 01, 2019 at 01:24:39PM +0200, Maxime Chevallier wrote: > I agree that this the real solution, it just seemed a bit overwhelming > to me. I'll be happy to help with this though, now that you took a big > first step. I think the first step is to resurrect my original patch to default to a 32-bit DMA mask for platform devices, as that will cut a lot of crap from the platform device declarations. IIRC the problem back then was that USB uses the fact that a DMA mask exist to decide if it uses a DMA vs PIO path in the HCD core. So I'll need some help from Greg or other USB folks to clean that up, after that we can try to apply my patch again (preferably early in the next merge window), and once that sticks clean up all the 32-bit dma mask initialization for platform devices, and then turn the dma_mask into a scalar.