Re: [PATCH v5 0/5] Add ARM Mali Midgard device tree bindings and gpu node for rk3288

[Guillaume Tucker]

On 09/05/17 02:16, Randy Li wrote:
> On 05/09/2017 12:27 AM, Heiko StÃbner wrote:
> > Am Mittwoch, 3. Mai 2017, 10:56:24 CEST schrieb Guillaume Tucker:
> > > The ARM Mali Midgard GPU kernel driver is only available
> > > out-of-tree and is not going to be merged in its current form.
> > > However, it would be useful to have its device tree bindings
> > > merged.  In particular, this would enable distributions to create
> > > working driver packages (dkms...) without having to patch the
> > > kernel.
> > >
> > > The bindings for the earlier Mali Utgard GPU family have already
> > > been merged, so this is essentially the same scenario but for
> > > newer GPUs (Mali-T604 ~ Mali-T880).
> > >
> > > This series of patches first imports the bindings from the latest
> > > driver release with some clean-up then adds a gpu node for the
> > > rk3288 SoC.  This was successfully tested on Radxa Rock2 Square,
> > > Firefly, Veyron Minnie and Jerry boards using Mali kernel driver
> > > r16p0 and r12p0 user-space binary.
> I won't suggest such combine. We meet some problems at mali 400 serial.
> I would suggest the kernel version would match the user library.

Well, I can test it again with r12p0 kernel driver (out-of-tree)
if you want.  The user-space driver checks the version of the
kernel driver and gives up if it's not compatible.  With Midgard,
there's a range of versions that maintain kernel/userspace
compatibility unlike Utgard and older Midgard releases where they
had to exactly match.  Again, if there was a mismatch then the
user-space would fail to initialise and report an error.

> Also please notice there is rk3288w, the hardware version becomes r1p0.

Sounds like a new SoC?  Does rk3288w affect rk3288 in any way?

Unless it's a special case, it seems to me that any new SoC with
a Midgard GPU would need an extra vendor compatible string in the
binding documentation and maybe a separate gpu dt node.

> > The actual devicetree parts are all Rockchip-specific, so I guess I'll just
> > pick up the whole series, including the binding doc, after the merge
> > window if nobody complains before that :-)

Thanks!


Guillaume