[Buildroot] [PATCH] package/mesa3d: gbm needs a DRI driver or a Gallium driver w/ EGL

[Yann E. MORIN]

Romain, All,

On 2020-02-22 20:40 +0100, Yann E. MORIN spake thusly:
> On 2020-02-19 20:10 +0100, Romain Naour spake thusly:
> > src/gbm/cd6bfad@@gbm at sha/main_backend.c.o: In function `_gbm_create_device':
> > backend.c:(.text+0x38): undefined reference to `gbm_dri_backend'
> > backend.c:(.text+0x40): undefined reference to `gbm_dri_backend'
> > backend.c:(.text+0x74): undefined reference to `gbm_dri_backend'
> > backend.c:(.text+0x78): undefined reference to `gbm_dri_backend'
> > collect2: error: ld returned 1 exit status
> > 
> > This issue has been trigged since [1]:
> > "package/mesa3d: add option to configure gbm support"
> > 
> > Before the patch, the gbm support was autodetected by meson and enabled
> > only when at least one dri driver was enabled [2].
> > 
> > On the Buildroot side, the gbm support was explicitely enabled only when
> > BR2_PACKAGE_MESA3D_OPENGL_EGL was set.
> > 
> > We have two cases:
> > - At least one DRI driver.
> > - No DRI driver but one Gallium w/ EGL enable (EGL selected or not by the
> >   Gallium driver). In this case the meson build system set with_dri to true
> >   (even if no DRI driver is enabled) to use the builtin:egl_dri2 [3].
> > 
> > The gbm's meson build system seems to handle the case where no dri driver is
> > enabled [4] but it still use main/backend.c source file [6] that use
> > gbm_dri_backend [7]. So with_dri2 must always be set.
> > 
> > Probably a missing check in meson.build:
> > 
> >  if with_gbm and not with_dri
> >    error('GBM backend needs a dri driver or a gallium driver w/ EGL support.')
> >  endif
> > 
> > Add a dependency on GBM option:
> > 
> >  depends on BR2_PACKAGE_MESA3D_DRI_DRIVER \
> >          || (BR2_PACKAGE_MESA3D_GALLIUM_DRIVER && BR2_PACKAGE_MESA3D_OPENGL_EGL)
> > 
> > Fixes:
> > http://autobuild.buildroot.net/results/b9b6281983388dc22d929887d653da3db60f1f2c
> > 
> > [1] b6c051acf787c804e732bc58ba8d7e440701a168
> > [2] https://gitlab.freedesktop.org/mesa/mesa/blob/19.3/meson.build#L348
> > [3] https://gitlab.freedesktop.org/mesa/mesa/blob/19.3/meson.build#L212
> > [4] https://gitlab.freedesktop.org/mesa/mesa/blob/19.3/src/gbm/meson.build#L37
> > [5] https://gitlab.freedesktop.org/mesa/mesa/blob/19.3/src/gbm/meson.build#L24
> > [6] https://gitlab.freedesktop.org/mesa/mesa/blob/19.3/src/gbm/main/backend.c#L38
> > [7] http://lists.busybox.net/pipermail/buildroot/2020-February/274425.html
> > 
> > Signed-off-by: Romain Naour <romain.naour at smile.fr>
> > Cc: Bernd Kuhls <bernd.kuhls at t-online.de>

And,,, Applied to master, thanks.

Regards,
Yann E. MORIN.

> So, with the other patch you sent later (and that I already applied),
> the conditions for gbm are now very strict, to the point where there is
> only three conditions under wich it is freely selectable: one of the DRI
> drivers is enabled, *and* OSMesa is enabled.
> 
> Now, gbm depends on Galium and EGL, but EGL forcibly selects GBM.
> 
> So the comment that states "gbm needs [...] gallium and EGL", alrhough
> technically correct, is totally useless, because enabling EGL gives no
> choice as it forcibly enables gbm.
> 
> I know mesa3d is complex, but our packaging of it really looks like it
> is overly complicated for no good reasons. It evolved organically over
> the years, and probably now is a good time for a full revamp of the
> package.
> 
> Any taker?
> 
> Regards,
> Yann E. MORIN.
> 
> > ---
> >  package/mesa3d/Config.in | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/package/mesa3d/Config.in b/package/mesa3d/Config.in
> > index dbfc59bad5..0788f47137 100644
> > --- a/package/mesa3d/Config.in
> > +++ b/package/mesa3d/Config.in
> > @@ -400,9 +400,15 @@ comment "OpenGL API Support"
> >  
> >  config BR2_PACKAGE_MESA3D_GBM
> >  	bool "gbm"
> > +	depends on BR2_PACKAGE_MESA3D_DRI_DRIVER \
> > +		|| (BR2_PACKAGE_MESA3D_GALLIUM_DRIVER && BR2_PACKAGE_MESA3D_OPENGL_EGL)
> >  	help
> >  	  Enable Generic Buffer Management (gbm)
> >  
> > +comment "gbm support needs a dri driver or a gallium driver w/ EGL support."
> > +	depends on !BR2_PACKAGE_MESA3D_DRI_DRIVER \
> > +		|| !(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER && BR2_PACKAGE_MESA3D_OPENGL_EGL)
> > +
> >  config BR2_PACKAGE_MESA3D_OPENGL_GLX
> >  	bool "OpenGL GLX"
> >  	depends on BR2_PACKAGE_XORG7
> > -- 
> > 2.21.1
> > 
> > _______________________________________________
> > buildroot mailing list
> > buildroot at busybox.net
> > http://lists.busybox.net/mailman/listinfo/buildroot
> 
> -- 
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-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 561 099 427 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'