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

[H. Nikolaus Schaller]

Hi Adam,

> Am 23.01.2018 um 15:30 schrieb Adam Ford <aford173 at gmail.com>:
> 
> On Tue, Jan 23, 2018 at 7:48 AM, Tomi Valkeinen <tomi.valkeinen at ti.com> wrote:
>> Hi,
>> 
>> On 23/01/18 15:38, H. Nikolaus Schaller wrote:
>>> In the end we should have a single, generic SGX driver for all OMAP SoC variants
>>> sitting in mainline drivers/gpu/pvr. So the goal is to end the era of out-of
>>> tree SGX drivers for a significant portion of OMAP processors.
>> 
>> I don't think that will ever happen, because there is no open source
>> userspace library for SGX. That library is the "real" driver here. At
>> least the policy has been (I believe it still is) that you can't have a
>> driver in the kernel which can only be used with a closed source
>> userspace component.
>> 
> 
> TI maintains some sort of SGX library on their git repo if I am not
> mistaken.

Yes, there are some parts and I fetched the ompa4+5 tree from

git://git.ti.com/graphics/omap5-sgx-ddk-linux.git

but the last commit is 3 years old.

>  If we as a community can get the kernel setup enough and
> provide TI with patches to make the SGX library work again with omap36
> and OMAP35 processors, would TI accept patches to their library?

It would be an alternative, but the key task is to get a team
willing to fix, maintain and update things. The location of the git
repo is a little arbitrary, although I'd prefer kernel.org to
address the broadest public.

And to keep the big picture in mind, there are non-TI SoC using
the same PVR/SGX which I hope will finally merge. This would become
a little more difficult if the work is done on the TI git where
it is probably not easy to get push access.

>  With
> the changes so far, we're pretty close to getting the kernel the
> necessary infrastructure to setup/configure the hardware and provide
> the closed source blobs the necessary hooks to operate.
> 
> Secondly, Nikolaus and Tony have done a great job in trying to get the
> hwmods and reset stuff working (mostly) for the omap36 and to some
> extent the am33x.    Would it be possible to get some TI assistance in
> determining what work is left to re-integrate compatibility into
> either the DRM of FB drivers?  The SGX drivers appear to have been
> broken for years and mostly abandoned by TI. I know the OMAP3, OMAP4
> and AM33 are older architectures, but having TI provide the remaining
> assistance would go a long way in showing they still care about their
> products.

Indeed!

BR,
Nikolaus