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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 67D4FC4727E for ; Wed, 30 Sep 2020 16:46:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02AD92076B for ; Wed, 30 Sep 2020 16:46:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="e5yEacMl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731353AbgI3QqY (ORCPT ); Wed, 30 Sep 2020 12:46:24 -0400 Received: from crapouillou.net ([89.234.176.41]:37354 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgI3QqX (ORCPT ); Wed, 30 Sep 2020 12:46:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1601484381; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kcU9yGQD6B2scIkP8pZMunYb7NCYboP62O9RzuBiMUg=; b=e5yEacMlg4Kfj0LdZISIy62btPD+Kf07vKS+EHO4xQptlsFf8HdJuhMyyohm8+crHHHjSy jsX5npmo3IfEfkAqRz17BIf7NIMxcagguh/dm9LMoVZghVcOhmCUXXBeLmYGpPKaSqVWg/ aT8C+t/LQY7FXAkOcXDLdPQTGnjLBmM= Date: Wed, 30 Sep 2020 18:45:02 +0200 From: Paul Cercueil Subject: Re: linux-next: build failure after merge of the drm tree To: Christoph Hellwig Cc: Stephen Rothwell , Dave Airlie , DRI , Linux Next Mailing List , Linux Kernel Mailing List Message-Id: <27DHHQ.SLESFBOY1GXP1@crapouillou.net> In-Reply-To: <20200930164023.GA8645@lst.de> References: <20200928060427.GA15041@lst.de> <20200928113415.GA555@lst.de> <72ADHQ.T6LL1SHQF0RG3@crapouillou.net> <20200928121002.GA3219@lst.de> <20200930090252.GA9357@lst.de> <20200930161124.GA6859@lst.de> <20200930164023.GA8645@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le mer. 30 sept. 2020 =E0 18:40, Christoph Hellwig a =E9crit=20 : > On Wed, Sep 30, 2020 at 06:39:18PM +0200, Paul Cercueil wrote: >>> dma_alloc_pages gives you cached memory, so you can't just use an >>> uncached protection for the userspace mmap here. If you want=20 >>> uncached >>> memory you need to use dma_alloc_coherent paired with=20 >>> dma_mmap_coherent. >>> Or dma_alloc_wc for a slightly different flavor of uncached. (both >>> of the map to dma_alloc_attrs / dma_mmap_attrs eventually). >>=20 >> I don't want uncached memory, I want non-coherent cached memory. >=20 > We don't have such a thing in the Linux API at all. dma_pgprot(dev, vma->vm_page_prot, DMA_ATTR_NON_CONSISTENT); That was giving me non-coherent cached memory, and now I don't have an=20 alternative. -Paul