On Tue, 16 Jun 2020 at 18:20, Dmitry Osipenko digetx@gmail.com wrote:
16.06.2020 18:48, Emil Velikov пишет:
On Tue, 16 Jun 2020 at 12:40, Dmitry Osipenko digetx@gmail.com wrote:
16.06.2020 01:26, Emil Velikov пишет:
Hi Dmitry,
On Mon, 15 Jun 2020 at 08:28, Dmitry Osipenko digetx@gmail.com 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-... [2] https://github.com/grate-driver/xf86-video-opentegra/commit/28eb20a3959bbe5b... [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.
You're spot on - it is/should be a generic property.
I believe that in general many panels were mounted in the correct orientation so the property, kernel and userspace were slow to catch up. In some cases panels will use flip x+y to denote 180 rotation, yet lacking the rotation property. The s6e8aa0 is an example of the last oddity. To make it better, the two dts in-tree always set both flip x and y.
Tl;Dr: Hysterical raisins
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.
That's why I mentioned the rotation introduction or "confusion" if I may. Skimming through the pre/post YAML device tree bindings and grep through the panel themselves will greatly reduce the list. In other words: if neither binding documentation/in-tree dts nor panel mentions rotation - omit it.
-Emil