[Linux-stm32] [PATCH V3 13/22] ARM: dts: stm32: Enable GPU on AV96

[Lucas Stach]

Am Mittwoch, den 01.04.2020, 14:21 +0200 schrieb Marek Vasut:
> On 4/1/20 11:59 AM, Alexandre Torgue wrote:
> > Hi Marek
> 
> Hi,
> 
> > On 3/31/20 7:58 PM, Marek Vasut wrote:
> > > Enable the GPU present on the STM32MP1 populated on AV96.
> > > 
> > > Reviewed-by: Manivannan Sadhasivam <
> > > manivannan.sadhasivam at linaro.org>
> > > Signed-off-by: Marek Vasut <marex at denx.de>
> > > Cc: Alexandre Torgue <alexandre.torgue at st.com>
> > > Cc: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> > > Cc: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
> > > Cc: Patrice Chotard <patrice.chotard at st.com>
> > > Cc: Patrick Delaunay <patrick.delaunay at st.com>
> > > Cc: linux-stm32 at st-md-mailman.stormreply.com
> > > To: linux-arm-kernel at lists.infradead.org
> > > ---
> > > V2: No change
> > > V3: No change
> > > ---
> > >   arch/arm/boot/dts/stm32mp157a-avenger96.dts | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/arch/arm/boot/dts/stm32mp157a-avenger96.dts
> > > b/arch/arm/boot/dts/stm32mp157a-avenger96.dts
> > > index 27c48f988540..19a7a130b148 100644
> > > --- a/arch/arm/boot/dts/stm32mp157a-avenger96.dts
> > > +++ b/arch/arm/boot/dts/stm32mp157a-avenger96.dts
> > > @@ -139,6 +139,10 @@ phy0: ethernet-phy at 7 {
> > >       };
> > >   };
> > >   +&gpu {
> > > +    status = "okay";
> > > +};
> > > +
> > 
> > GPU is now enable by so you can drop this patch.
> 
> Why is it enabled by default ? That's somewhat useless on headless
> systems.

The better question is: why wouldn't it be enabled by default? It's a
SoC peripheral and has no external dependencies. Even on a headless
system you can still do stuff like color conversion/balancing via GL in
a video pipeline or something like this. There is simply no good reason
to hide the existence of the GPU.

If you are really concerned about the few ms it takes to initialize the
GPU on boot, you can always choose to not build the driver, or use a
specific DT for your use-case.

Regards,
Lucas