From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934221AbcIOODG (ORCPT ); Thu, 15 Sep 2016 10:03:06 -0400 Received: from mail-yw0-f176.google.com ([209.85.161.176]:36166 "EHLO mail-yw0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758047AbcIOOCu (ORCPT ); Thu, 15 Sep 2016 10:02:50 -0400 MIME-Version: 1.0 In-Reply-To: <1473857701-9250-1-git-send-email-tfiga@chromium.org> References: <1473857701-9250-1-git-send-email-tfiga@chromium.org> From: Sean Paul Date: Thu, 15 Sep 2016 10:02:26 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 0/8] drm/rockchip: Flip wait clean-up To: Tomasz Figa Cc: dri-devel , Linux ARM Kernel , linux-rockchip@lists.infradead.org, Linux Kernel Mailing List , Heiko Stuebner , David Airlie , Mark Yao , Daniel Kurtz Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 14, 2016 at 8:54 AM, Tomasz Figa wrote: > The display controller found on Rockchip SoCs supported by Rockchip DRM > driver (VOP) is a bit problematic, because it does not provide hardware > vblank counter. Because vblank interrupt is used to feed the software > counter, the driver had custom code to wait for flip completion to avoid > race between atomic flush and vblank interrupt handler. > > This, however, brought a different set of issues. In fact, even with the > custom wait code, there is stil a race between the handler and driver > state update (of the values used to compare with registers to determine > if flip has completed). On top of that, legacy cursor updates are not > implemented properly and have to wait for vblank to complete, which > is against the API specification. > > This series attempts to clean up the driver from this custom waiting code, > eliminating related races and bringing correct handling of legacy cursor > plane. It also gives a nice effect of more than 100 lines of code removed. > > This is a forward port of patches from 4.4 kernel used by ChromiumOS and > tested there. Even though the code base has not changed significantly, it > would be nice if someone with proper testing environment could give them > a try. > > Based on for-next branch of Sean Paul's dogwood tree: > https://cgit.freedesktop.org/~seanpaul/dogwood/log/?h=for-next > git://people.freedesktop.org/~seanpaul/dogwood > Thanks for the patches, Tomasz. I'll queue them up in my rockchip for-next branch. Sean > Tomasz Figa (8): > drm/rockchip: Clear interrupt status bits before enabling > drm/rockchip: Get rid of some unnecessary code > drm/rockchip: Avoid race with vblank count increment > drm/rockchip: Unreference framebuffers from flip work > drm/rockchip: Replace custom wait_for_vblanks with helper > drm/rockchip: Do not enable vblank without event > drm/rockchip: Always signal event in next vblank after cfg_done > drm/rockchip: Kill vop_plane_state > > drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 1 - > drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 64 +------ > drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 247 +++++++++++----------------- > 3 files changed, 95 insertions(+), 217 deletions(-) > > -- > 2.8.0.rc3.226.g39d4020 >