[Buildroot] [PATCH v2 1/7] package/opengl/libgbm: new virtual package

[Kamel Bouhara]

On Fri, Oct 01, 2021 at 04:13:54PM +0200, Thomas Petazzoni wrote:
> Hello,
>

Hello Thomas,

> On Wed, 29 Sep 2021 00:37:48 +0200
> Kamel Bouhara <kamel.bouhara at bootlin.com> wrote:
>
> > From: Bernd Kuhls <bernd.kuhls at t-online.de>
> >
> > Kodi 18.0-Leia will implement stand-alone gbm support alongside x11 &
> > wayland.  To enable building libgbm in mesa3d without x11 & wayland we
> > need to create a virtual package for libgbm.
> >
> > Also other packages besides mesa3d may provide libgbm.so, see
> > http://patchwork.ozlabs.org/patch/647235/
> > http://patchwork.ozlabs.org/patch/939703/
> >
> > We also introduce two feature that shall help user choosing the version
> > implemented by a libgbm provider. This foresightly avoid building package
> > without having the required libgbm version (e.g. kmscube, qt5, sdl2
> > etc.)
>
> I would rephrase this as such:
>
> """
> It turns out that libgbm has seen several additions in its API over
> time, and therefore not all libgbm implementations provide support for
> all features. In order to account for this, this commit adds two hidden
> boolean options that allow libgbm providers to indicate which optional
> features they support:
> BR2_PACKAGE_LIBGBM_HAS_FEATURE_FORMAT_MODIFIER_PLANE_COUNT and
> BR2_PACKAGE_LIBGBM_HAS_FEATURE_DMA_BUF. These booleans must be selected
> by the packages providing libgbm implementations, and depended on by
> packages using libgbm.
> """
>

OK.

> Question: do we have in the tree some libgbm implementation that
> support neither
> BR2_PACKAGE_LIBGBM_HAS_FEATURE_FORMAT_MODIFIER_PLANE_COUNT nor
> BR2_PACKAGE_LIBGBM_HAS_FEATURE_DMA_BUF ?

So far, the dma buf feature (mesa gbm v10) is provided by every
implementation I compared (gcnano, ti, sunxi, imx-gpu).

Thanks for the review, sending a v3 soon.

Kamel

>
> > diff --git a/package/opengl/libgbm/Config.in b/package/opengl/libgbm/Config.in
> > new file mode 100644
> > index 0000000000..7aa3efb97a
> > --- /dev/null
> > +++ b/package/opengl/libgbm/Config.in
> > @@ -0,0 +1,24 @@
> > +config BR2_PACKAGE_HAS_LIBGBM
> > +	bool
> > +
> > +config BR2_PACKAGE_PROVIDES_LIBGBM
> > +	string
> > +	depends on BR2_PACKAGE_HAS_LIBGBM
> > +
> > +config BR2_PACKAGE_LIBGBM_HAS_FEATURE_FORMAT_MODIFIER_PLANE_COUNT
> > +	bool
> > +	depends on BR2_PACKAGE_HAS_LIBGBM
> > +
> > +# gbm implementations should select this option if they provide the
> > +# format modifier plane count feature. This API was initially introduced
> > +# in mesa3d version 17. A gbm implementation provides this feature if it
> > +# is implement function gbm_device_get_format_modifier_plane_count.
>
> The comment should be before the option.
>
> > +config BR2_PACKAGE_LIBGBM_HAS_FEATURE_DMA_BUF
> > +	bool
> > +	depends on BR2_PACKAGE_HAS_LIBGBM
> > +
> > +# gbm implementations should select this option if they provide the
> > +# dma buffer feature. This API was initially introduced in mesa3d
> > +# version 10. A gbm implementation provides this feature if it
> > +# is implement function gbm_bo_get_fd.
>
> Ditto.
>
> Note: no need to resend to address those comments, they can be fixed up
> when applying.
>
> Best regards,
>
> Thomas
> --
> Thomas Petazzoni, co-owner and CEO, Bootlin
> Embedded Linux and Kernel engineering and training
> https://bootlin.com

--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com