after I read the code of mali-400/450 linux kernel driver r3p2-01rel4, I have a doubt that if it is really able to support DRM.
(because of the lack of Mali device, I failed to give a try)
Take an example from drm_sman_mm, Mali's drm_sman_mm callbacks almost do nothing.
so, I wonder how these code provides support for drm.
one extra question, if anyone ever happens to read the code, in Mali's drm_sman_mm related macros
#define VIDEO_TYPE 0
#define MEM_TYPE 1
Does the first represents discrete VRAM, the latter shared system memory?
Best Regards,
Michael
Hello Michael,
Firstly I would like to apologise for the late reply...
Mali is a GPU, not a display controller, so it isnt the one which is actually putting pixels onto the screen, it only renders things to memory. It is the display controller driver who then takes that memory and puts it to the screen.
As such, most of DRM is not applicable to Mali, but is needed for the display controller. mali_drm is just a thin layer which uses DRM ioctls in the DDX driver.
In addition to this, Mali does not use all of the DRM functionalities that modern Desktop GPU's use, due to it not being relevant to embedded GPU's.
I hope this helped explain things for you... if you have additional questions, feel free to ask.
Kind Regards,
Michael McGeagh