[Letux-kernel] Lay common foundation to make PVR/SGX work without hacks on OMAP34xx, OMAP36xx, AM335x and potentially OMAP4, OMAP5

[Tony Lindgren]

Hi,

* H. Nikolaus Schaller <hns at goldelico.com> [180125 09:46]:
> > Am 24.01.2018 um 08:45 schrieb Tomi Valkeinen <tomi.valkeinen at ti.com>:
> > And, again, my understanding of the "DRM philosophy" is that having
> > kernel drivers like these is explicitly forbidden in the mainline. Which
> > is why e.g. there's no nvidia kernel driver.
> 
> Well, if the "DRM philosophy" requires to modify the communication protocols
> between the sgx libs and the sgx microkernel, then we have a problem.

Well we already have minimal sgx540 2d acceleration in the mainline
kernel in the intel driver drivers/gpu/drm/gma500. So we could share
that code and do a drm sgx driver based on that.

Sure it won't be probably any faster, but still handles the hardware
so then anybody who wants to can attempt to patch it further.

To see the sgx540 read and write access in the driver:

$ git grep [RW]SGX drivers/gpu/drm/gma500/

Then see drivers/gpu/drm/gma500/accel_2d.c for psbfb_copyarea()
and psbfb_copyarea_accel().

Regards,

Tony