Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753307AbeADOvP (ORCPT + 1 other); Thu, 4 Jan 2018 09:51:15 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:38746 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753092AbeADOvM (ORCPT ); Thu, 4 Jan 2018 09:51:12 -0500 X-Google-Smtp-Source: ACJfBotMXXvXTzqpI+Q8eID0dzMXouhbl7XMFnt6R4SsA3hBzcQJjnzZunt7RY/bLu5jfIGzjl0CbQ== MIME-Version: 1.0 In-Reply-To: References: From: Chen-Yu Tsai Date: Thu, 4 Jan 2018 22:50:49 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 11/12] drm/sun4i: backend: Make sure we don't have a commit pending To: Maxime Ripard Cc: Daniel Vetter , David Airlie , dri-devel , linux-kernel , linux-arm-kernel , Thomas Petazzoni , Neil Armstrong , thomas@vitsch.nl Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Mon, Dec 18, 2017 at 10:57 PM, Maxime Ripard wrote: > If we try to read the backend registers while it fetches the new values, we > end up with the value of some random register instead of the one we asked > for. > > In order to prevent that, let's make sure that the very first thing we do > during our atomic modesetting is to let the commit bit come to a rest. > > We don't have to worry about anything else since the only time we will > trigger a new transaction is during the atomic_commit which comes much > later. > > Signed-off-by: Maxime Ripard Reviewed-by: Chen-Yu Tsai