From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752383AbcBWXcq (ORCPT ); Tue, 23 Feb 2016 18:32:46 -0500 Received: from mail.kmu-office.ch ([178.209.48.109]:35331 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751155AbcBWXco (ORCPT ); Tue, 23 Feb 2016 18:32:44 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Tue, 23 Feb 2016 15:30:03 -0800 From: Stefan Agner To: dri-devel@lists.freedesktop.org, thierry.reding@gmail.com Cc: airlied@linux.ie, daniel.vetter@ffwll.ch, jianwei.wang.chn@gmail.com, alison.wang@freescale.com, meng.yi@nxp.com, linux@arm.linux.org.uk, p.zabel@pengutronix.de, denis@eukrea.com, eric@eukrea.com, ville.syrjala@linux.intel.com, linux-kernel@vger.kernel.org, manfred.schlaegl@gmx.at, tomi.valkeinen@ti.com, linux@arm.linux.org.uk, boris.brezillon@free-electrons.com Subject: Re: [PATCH v2 0/3] drm: introduce bus_flags for pixel clock polarity In-Reply-To: <1454968663-30066-1-git-send-email-stefan@agner.ch> References: <1454968663-30066-1-git-send-email-stefan@agner.ch> Message-ID: <653e3f9d2d561a166a1768add0c59422@agner.ch> User-Agent: Roundcube Webmail/1.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Any comments on this? Also added Manfred, Tomi and Boris to CC which previously attended in similar discussions. Previous discussions: http://thread.gmane.org/gmane.linux.kernel.api/12830 http://thread.gmane.org/gmane.comp.video.dri.devel/96240/ I think one of the main observation so far was that the pixel clock polarity is not a property of the mode, and therefor does not fit into the DRM_MODE_FLAG. This has been pointed out nicely by Russel: http://thread.gmane.org/gmane.comp.video.dri.devel/96240/focus=96260 Embedded displays connected through parallel bus make use of the bus_formats field in drm_display_mode. This field defines what kind of bus format the display requires. This patch follows that idea and adds bus_flags. bus_flags can be used to define specific bus properties required by the display, such as pixel clock or data enable polarity... On 2016-02-08 13:57, Stefan Agner wrote: > Hi, > > This is a new & split out version of the last patch of my > "drm/fsl-dcu: fixes and enhancements" patchset: > https://lkml.org/lkml/2015/11/18/949 > > Instead of using struct drm_display_mode to convey the pixel clock > polarity information, this patchset introduces a new field called > bus_flags stored in struct drm_display_info. Note that this solution has been briefly discussed on IRC: https://people.freedesktop.org/~cbrill/dri-log/?channel=dri-devel&highlight_names=&date=2016-02-08 -- Stefan > > Changes since v1: > - Introduce bus_flags to convey the pixel clock polarity from > panel-simple.c to the driver. > > Stefan Agner (3): > drm/fsl-dcu: use mode flags for hsync/vsync polarity > drm: introduce bus_flags in drm_display_info > drm/fsl-dcu: use bus_flags for pixel clock polarity > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c | 16 +++++++++++++--- > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 4 ++-- > drivers/gpu/drm/panel/panel-simple.c | 6 +++++- > include/drm/drm_crtc.h | 9 +++++++++ > 4 files changed, 29 insertions(+), 6 deletions(-)