Den 02.04.2022 19.55, skrev Marek Vasut: > On 4/2/22 19:08, Noralf Trønnes wrote: >> >> >> Den 02.04.2022 18.39, skrev Marek Vasut: >>> On 4/2/22 09:45, Noralf Trønnes wrote: >>>> >>>> >>>> Den 02.04.2022 06.28, skrev Marek Vasut: >>>>> On 4/2/22 05:19, Laurent Pinchart wrote: >>>>>> On Fri, Apr 01, 2022 at 10:36:24PM +0200, Marek Vasut wrote: >>>>>>> On 4/1/22 20:46, Laurent Pinchart wrote: >>>>>>>> On Fri, Apr 01, 2022 at 06:37:54PM +0200, Marek Vasut wrote: >>>>>>>>> Make the width-mm/height-mm panel properties mandatory in >>>>>>>>> of_get_drm_panel_display_mode(), print error message and >>>>>>>>> return -ve in case these DT properties are not present. >>>>>>>>> This is needed to correctly report panel dimensions. >>>>>>>> >>>>>>>> Can we guarantee this won't cause a regression ? >>>>>>> >>>>>>> For the upstream DTs, I think we can. >>>>>>> For downstream DTs, we cannot know. >>>>>> >>>>>> Are there users of this function whose DT bindings don't require the >>>>>> width-mm and height-mm properties ? >>>>> >>>>> There is literally one user of this function upstream: >>>>> drivers/gpu/drm/tiny/panel-mipi-dbi.c >>>> >>>> Yes, the function was added for that driver since it was so generic in >>>> nature. What about adding an argument to >>>> of_get_drm_panel_display_mode() >>>> that tells if the properties are mandatory or not? >>> >>> Sure, we can do that, but maybe the question here is even bigger than >>> this series. >>> >>> Should every panel set mandatory width_mm/height_mm so e.g. the user >>> space can infer DPI from it and set up scaling accordingly, or should >>> width_mm/height_mm be optional ? >>> >>> I think width_mm/height_mm should be mandatory for all panels. >>> >>> Thoughts ? >> >> If this had come up during the review of the driver I would have no >> problem making it mandatory. It makes sense for DPI. Maybe it's possible >> to get around the ABI break by getting in a change through -fixes before >> 5.18 is released? I'm fine with that. > > Well that's awesome, the dbi-spi.yaml didn't land in any kernel release > yet, so we still have a chance to fix it ? It entered this merge window.
