From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: [PATCH v5 2/7] drm/panel: simple: Add ability to override typical timing Date: Mon, 8 Jul 2019 19:56:06 +0200 Message-ID: <20190708175606.GB3511@ravnborg.org> References: <20190401171724.215780-1-dianders@chromium.org> <20190401171724.215780-3-dianders@chromium.org> <20190630202246.GB15102@ravnborg.org> <20190630205514.GA17046@ravnborg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Doug Anderson Cc: devicetree@vger.kernel.org, David Airlie , Jeffy Chen , LKML , Rob Herring , "open list:ARM/Rockchip SoC..." , Thierry Reding , Sean Paul , dri-devel , Boris Brezillon , Enric =?iso-8859-1?Q?Balletb=F2?= , =?iso-8859-1?Q?St=E9phane?= Marchesin , Ezequiel Garcia , Matthias Kaehlcke , Laurent Pinchart List-Id: devicetree@vger.kernel.org On Mon, Jul 01, 2019 at 09:39:06AM -0700, Doug Anderson wrote: > Hi, > > On Sun, Jun 30, 2019 at 1:55 PM Sam Ravnborg wrote: > > > > Hi Douglas. > > > > > > + > > > > + /* Only add timings if override was not there or failed to validate */ > > > > + if (num == 0 && panel->desc->num_timings) > > > > + num = panel_simple_get_timings_modes(panel); > > > > + > > > > + /* > > > > + * Only add fixed modes if timings/override added no mode. > > > > > > This part I fail to understand. > > > If we have a panel where we in panel-simple have specified the timings, > > > and done so using display_timing so with proper {min, typ, max} then it > > > should be perfectly legal to specify a more precise variant in the DT > > > file. > > > Or what did I miss here? > > > > Got it now. > > If display_mode is used for timings this is what you call "fixed mode". > > Hmm, if I got confused someone else may also be confused by this naming. > > The name "fixed mode" comes from the old code, though I guess in the > old code it used to refer to a mode that came from either the > display_timing or the display_mode. > > How about if I call it "panel_simple_get_from_fixed_display_mode"? > ...or if you have another suggestion feel free to chime in. What we really want to distingush here is the use of display_mode and display_timings (if I got the names right). That display_mode specify a fixed timing and display_timing specify a valid range is something in the semantics of the two types. So naming that refer to display_mode versus display_timing will make the code simpler to understand. and then a nice comment that when display_mode is used one looses the possibility to use override_mode. That would be fine to have in the struct in the driver. > NOTE: Since this feedback is minor and this patch has been outstanding > for a while (and is blocking other work), I am assuming that the best > path forward is for Heiko to land this patch with Thierry's Ack and > I'll send a follow-up. Please yell if you disagree. Let's give the patches a spin more as we have passed the possibility for the current merge window. I am on vacation at the moment and thus slow in responses, but will be back at the home office next week and will be more responsive again. Sam - who is enjoying the alps in Austria