[v3d, v3dv, BCM2711] Support for surface transforms?
Is it feasible to add support for surface transforms other than identity?
My use case is to drive a portrait DSI TFT-LCD panel and to rotate the surface 90 degrees such that displayed image is correct if the panel is in landscape orientation.
It is possible to do this using xrandr but there appears to be a significant overhead (presumably due a separate image copy during window composition?) and I would prefer to use the vkCreateDisplayPlaneSurfaceKHR interface instead.
I've had a peek through the various source and it appears as if this path isn't really supported. (It looks to me as if the v3dv driver calls through to common vulkan code, which doesn't seem to check if the GPU/DRM can handle surface transforms, simply setting VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR as the supported transform??).
Given the lack of VC6 documentation, I thought I'd ask here if the driver maintainers might know if this is actually feasible from a hardware point of view and if so, whether or not this might be on the roadmap for implementation in future?
Apologies if this is the wrong place to ask, please direct me elsewhere if so.
Many thanks for all the hard work on this Vulkan driver, it's very cool to be able to use this on pi4!