Re: [PATCH v10 0/2] Panel rotation patches

[Dmitry Osipenko <digetx@gmail.com>]

06.03.2020 03:21, Derek Basehore пишет:
> This adds the plumbing for reading panel rotation from the devicetree
> and sets up adding a panel property for the panel orientation on
> Mediatek SoCs when a rotation is present.

Hello Derek and everyone,

I'm looking at adding display rotation support to NVIDIA Tegra DRM
driver because some devices have display panel physically mounted
upside-down, and thus, display controller's scan-out needs to be rotated
by 180° in this case.

Derek, yours panel-rotation patches add support for assigning panel's
orientation to the connector, but then only primary display plane
receives rotation value in [1], while rotation needs to be applied to
all available overlay/cursor planes and this should happen in other
places than [1] as well.

[1] drm_client_modeset_commit_atomic()

Please also note that in a case of the scan-out rotation, plane's
coordinates need to be changed in accordance to the display's rotation.

I looked briefly through the DRM code and my understanding that the DRM
core currently doesn't support use-case where scan-out needs to rotated
based on a panel's orientation, correct? Is it the use-case you're
working on for the Mediatek driver?