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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 8873AC46470 for ; Tue, 7 Aug 2018 14:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4AECA21757 for ; Tue, 7 Aug 2018 14:14:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4AECA21757 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389412AbeHGQ2s (ORCPT ); Tue, 7 Aug 2018 12:28:48 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42320 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387617AbeHGQ2r (ORCPT ); Tue, 7 Aug 2018 12:28:47 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8CB0A87A74; Tue, 7 Aug 2018 14:14:15 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6BFAB2026D66; Tue, 7 Aug 2018 14:14:15 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id w77EEFrC013521; Tue, 7 Aug 2018 10:14:15 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id w77EEEm2013516; Tue, 7 Aug 2018 10:14:14 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Tue, 7 Aug 2018 10:14:13 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Ard Biesheuvel cc: Florian Weimer , Andrew Pinski , Richard Earnshaw , Ramana Radhakrishnan , Thomas Petazzoni , GNU C Library , Catalin Marinas , Will Deacon , Russell King , LKML , linux-arm-kernel Subject: Re: framebuffer corruption due to overlapping stp instructions on arm64 In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 07 Aug 2018 14:14:15 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 07 Aug 2018 14:14:15 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mpatocka@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 6 Aug 2018, Ard Biesheuvel wrote: > No that works fine for me. VDPAU acceleration works as well, but it > depends on your chromium build whether it can actually use it, I > think? In any case, mplayer can use vdpau to play 1080p h264 without > breaking a sweat on this system. > > Note that the VDPAU driver also relies on memory semantics, i.e., it > may use DC ZVA (zero cacheline) instructions which are not permitted > on device mappings. This is probably just glibc's memset() being > invoked, but I remember hitting this on another PCIe-impaired arm64 > system with Synopsys PCIe IP DC ZVA can be disabled with the SCTRL_EL1.DZE bit, so that neither kernel nor userspace will use it. If the mapping didn't support unaligned writes, it would be worse. Mikulas