On Sun, Jan 22, 2023 at 05:25:38PM +0000, Rayyan Ansari wrote: > On 22/01/2023 15:36, Rob Herring wrote: > > On Sat, Jan 21, 2023 at 9:36 AM Rayyan Ansari <rayyan@xxxxxxxxx> wrote: > > > > > > > Why do you need this change? > > > > The 'simple-framebuffer' contains data on how the bootloader > > configured the display. The bootloader doesn't configure the display > > size, so this information doesn't belong here. The information should > > already be in the panel node, so also no point in duplicating it here. > > > > > Signed-off-by: Rayyan Ansari <rayyan@xxxxxxxxx> > > > --- > > > .../devicetree/bindings/display/simple-framebuffer.yaml | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > Hi Rob, > > There is the usecase that Hans has mentioned, but I have also mentioned > another usecase previously. > > Adding the width-mm and height-mm properties allows user interfaces such as > Phosh (https://puri.sm/posts/phosh-overview/) to scale correctly to the > screen. In my case, a panel node is not available and the aforementioned > interface is in fact running on the SimpleDRM driver (which binds to the > simple-framebuffer device). Why is the panel node not available? Why not add it? Presumably it is not there because you aren't (yet) using the simple-panel driver (and others that would need). But presumably you will eventually as I'd imagine turning the screen off and back on might be a desired feature. So why add a temporary DT property that's tied to your *current* kernel? The DT should not be tightly coupled to the kernel. Rob
