From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Anderson Subject: Re: [PATCH v4 1/7] dt-bindings: Add panel-timing subnode to simple-panel Date: Fri, 29 Mar 2019 09:14:43 -0700 Message-ID: References: <20190328171710.31949-1-dianders@chromium.org> <20190328171710.31949-2-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring Cc: Ezequiel Garcia , Thierry Reding , Heiko Stuebner , Sean Paul , "open list:ARM/Rockchip SoC..." , Laurent Pinchart , dri-devel , Boris Brezillon , =?UTF-8?Q?Enric_Balletb=C3=B2?= , Matthias Kaehlcke , Eric Anholt , Jeffy Chen , =?UTF-8?Q?St=C3=A9phane_Marchesin?= , devicetree@vger.kernel.org, LKML , David Airlie , Mark Rutland , Daniel Vetter List-Id: dri-devel@lists.freedesktop.org Hi, On Fri, Mar 29, 2019 at 9:13 AM Rob Herring wrote: > > On Thu, Mar 28, 2019 at 6:50 PM Doug Anderson wro= te: > > > > Hi, > > > > > > On Thu, Mar 28, 2019 at 1:27 PM Ezequiel Garcia wrote: > > > > > > On Thu, 2019-03-28 at 10:17 -0700, Douglas Anderson wrote: > > > > From: Sean Paul > > > > > > > > This patch adds a new subnode to simple-panel allowing us to overri= de > > > > the typical timing expressed in the panel's display_timing. > > > > > > > > Changes in v2: > > > > - Split out the binding into a new patch (Rob) > > > > - display-timings is a new section (Rob) > > > > - Use the full display-timings subnode instead of picking the timi= ng > > > > out (Rob/Thierry) > > > > Changes in v3: > > > > - Go back to using the timing subnode directly, but rename to > > > > panel-timing (Rob) > > > > Changes in v4: > > > > - Simplify desc. for when override should be used (Thierry/Laurent= ) > > > > - Removed Rob H review since it's been a year and wording changed > > > > > > > > Cc: Doug Anderson > > > > Cc: Eric Anholt > > > > Cc: Heiko Stuebner > > > > Cc: Jeffy Chen > > > > Cc: Rob Herring > > > > Cc: St=C3=A9phane Marchesin > > > > Cc: Thierry Reding > > > > Cc: devicetree@vger.kernel.org > > > > Cc: dri-devel@lists.freedesktop.org > > > > Cc: linux-rockchip@lists.infradead.org > > > > Signed-off-by: Sean Paul > > > > Signed-off-by: Douglas Anderson > > > > --- > > > > > > > > .../bindings/display/panel/simple-panel.txt | 24 +++++++++++++++= ++++ > > > > 1 file changed, 24 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/display/panel/simple= -panel.txt b/Documentation/devicetree/bindings/display/panel/simple-panel.t= xt > > > > index b2b872c710f2..6157f86ddce4 100644 > > > > --- a/Documentation/devicetree/bindings/display/panel/simple-panel.= txt > > > > +++ b/Documentation/devicetree/bindings/display/panel/simple-panel.= txt > > > > @@ -15,6 +15,18 @@ Optional properties: > > > > (hot plug detect) signal, but the signal isn't hooked up so we s= hould > > > > hardcode the max delay from the panel spec when powering up the = panel. > > > > > > > > +panel-timing subnode > > > > +-------------------- > > > > + > > > > +This optional subnode is for devices which require a mode differin= g > > > > +from the panel's "typical" display timing. The panel timings prov= ided > > > > +here will be ignored if they are found to be outside of allowable > > > > +ranges for the given panel. > > > > + > > > > > > Is it OK to put this comment about how the implementation > > > will behave when values are out of range, given this is just a bindin= g > > > spec? > > > > > > Perhaps -if needed- this sentence can be rephrased to state that, > > > e.g. the OS may not be able to apply these values, if the controller > > > or device is unable to? > > > > I will defer to Rob H. on this one, but I'm happy to simply remove the > > last sentence. I was trying to add a more OS-agnostic version of the > > bullet points from V3 but agree that we could just remove this from > > the bindings completely. > > Following my opinion that it's not the kernel's job to validate > bindings, I would say it's fine for the OS to blindly apply them if it > chooses. > > Plus with schema, you can provide the ranges of values and validate > DTs up front (unless you want to validate some result of math > operations). OK, I'll remove the sentence and repost sometime early next week. Thanks! -Doug