On Tue, Jun 16, 2020 at 08:20:57PM +0300, Dmitry Osipenko wrote: > 16.06.2020 18:48, Emil Velikov пишет: > > On Tue, 16 Jun 2020 at 12:40, Dmitry Osipenko <digetx@xxxxxxxxx> wrote: > >> > >> 16.06.2020 01:26, Emil Velikov пишет: > >>> Hi Dmitry, > >>> > >>> On Mon, 15 Jun 2020 at 08:28, Dmitry Osipenko <digetx@xxxxxxxxx> wrote: > >>>> > >>>> Hello! > >>>> > >>>> This series adds 180° display plane rotation support to the NVIDIA Tegra > >>>> DRM driver which is needed for devices that have display panel physically > >>>> mounted upside-down, like Nexus 7 tablet device for example [1]. Since > >>>> DRM panel rotation is a new thing for a userspace, currently only > >>>> Opentegra Xorg driver handles the rotated display panel [2], but this > >>>> is good enough for the start. > >>>> > >>>> Note that later on it should be possible to implement a transparent 180° > >>>> display rotation for Tegra DRM driver which will remove the need to have > >>>> a bleeding edge userspace that knows how to rotate display planes and I'm > >>>> slowly working on it. For the starter we can go with the minimal rotation > >>>> support, so it's not a blocker. > >>>> > >>>> This series is based on the work that was made by Derek Basehore for the > >>>> Mediatek driver [3], his patch is included into this patchset. I added > >>>> my tested-by tag to the Derek's patch. > >>>> > >>>> Please review and apply, thanks in advance! > >>>> > >>>> [1] https://patchwork.ozlabs.org/project/linux-tegra/patch/20200607154327.18589-3-digetx@xxxxxxxxx/ > >>>> [2] https://github.com/grate-driver/xf86-video-opentegra/commit/28eb20a3959bbe5bc3a3b67e55977093fd5114ca > >>>> [3] https://lkml.org/lkml/2020/3/5/1119 > >>>> > >>>> Changelog: > >>>> > >>>> v2: - Dropped "drm/panel: Set display info in panel attach" patch, which > >>>> turned out to be obsolete now. > >>>> > >>>> - Renamed the cover-latter, hopefully this will fix the bouncing emails. > >>>> > >>>> Derek Basehore (1): > >>>> drm/panel: Add helper for reading DT rotation > >>>> > >>>> Dmitry Osipenko (4): > >>>> drm/panel: lvds: Set up panel orientation > >>> > >>> IMHO it's perfectly reasonable to report the panel orientation to > >>> userspace, which can apply plane rotation as needed. > >>> > >>> Although I see that this series, alike Derek's, has a couple of issues: > >>> - only a single panel driver is updated > >>> - rotation is _not_ listed as supported property, in said panel > >>> driver device-tree bindings > >>> > >>> My personal inclination is that we should aim for a comprehensive solution: > >>> - wire all panel drivers, as currently documented (quick grep list below) > >>> - document and wire-up the lvds and boe panels - as proposed by you > >>> and Derek respectively > >>> > >>> HTH > >>> Emil > >>> > >>> Documentation/devicetree/bindings/display/himax,hx8357d.txt:2 > >>> Documentation/devicetree/bindings/display/ilitek,ili9225.txt:2 > >>> Documentation/devicetree/bindings/display/ilitek,ili9341.txt:2 > >>> Documentation/devicetree/bindings/display/ilitek,ili9486.yaml:2 > >>> Documentation/devicetree/bindings/display/multi-inno,mi0283qt.txt:2 > >>> Documentation/devicetree/bindings/display/panel/panel-common.yaml:2 > >>> Documentation/devicetree/bindings/display/sitronix,st7586.txt:1 > >>> Documentation/devicetree/bindings/display/sitronix,st7735r.yaml:2 > >> > >> Rotation is a common DT panel property that is described in the > >> panel-common.yaml. > > The property was introduced almost exclusively for tiny drm panels. > > Those ones are a bit different from the rest (in panel/) - > > MIPI-DBI/SPI w/o (not connected at least) an actual GPU. > > > > To make it a bit better, the rotation is seemingly performed in the > > tiny driver itself ouch. > > > >> This property is supported by all panel bindings > >> because these bindings inherent the common properties from the > >> panel-common.yaml. > >> > > Seems like that was an unintentional change with the conversion to YAML. > > Beforehand only a few selected panels had rotation. Upon closer look - > > some panels do have follow-up fixes, to remove/limit the implicit > > inclusion. > > Interesting.. my understanding that the rotation property is supposed to > be a generic property which represents physical orientation of a display > panel and hence it should be applicable to all panels. Adding a bit more food for thoughts, the DT rotation property for camera sensor modules has recently been documented with lots of details. See https://lore.kernel.org/linux-media/20200509090456.3496481-3-jacopo@xxxxxxxxxx/, part of the documentation may be useful for panels. > > Sam seems like you've done most of the YAML conversion. IMHO it would > > make sense to revisit the patches and inherit common properties only > > as applicable. > > > >> I don't think that it makes sense to wire up rotation property to all > >> panel drivers at once because those drivers will be untested, at least I > >> don't know anything about those other panels and can't test them. It > >> will be much better to support the rotation on by as-needed basis for > >> each panel driver individually. > > > > How about CCing the author and reviewer asking them to test the patch? > > The only place where the patches might cause an issue is with tiny, > > although patches would still be appreciated. > > There are quite a lot of panel drivers and I'm a bit doubtful that at > least half of devices that use those panels have any real use for the > rotation property. I could write the patches.. but in the end it could > be a wasted effort if nobody needs it, so I'd prefer not to do it. -- Regards, Laurent Pinchart
