[Buildroot] [PATCH v1 1/2] package/mesa3d: add v3d driver support

[Yann E. MORIN <yann.morin.1998@free.fr>]

Peter, All,

On 2020-02-04 23:00 +0100, Peter Seiderer spake thusly:
> On Tue, 4 Feb 2020 22:45:40 +0100, Peter Seiderer <ps.report@gmx.net> wrote:
> > On Tue, 4 Feb 2020 21:55:16 +0100, "Yann E. MORIN" <yann.morin.1998@free.fr> wrote:
> > > On 2020-02-04 15:44 +0100, Peter Seiderer spake thusly:
> > > > Signed-off-by: Peter Seiderer <ps.report@gmx.net>
[--SNIP--]
> > > > +config BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D
> > > > +	bool "Gallium v3d driver"
> > > > +	depends on BR2_arm || BR2_aarch64
> > > > +	select BR2_PACKAGE_MESA3D_GALLIUM_DRIVER
> > > > +	select BR2_PACKAGE_MESA3D_GALLIUM_KMSRO
> > > > +	select )
> > > > +	select BR2_PACKAGE_MESA3D_OPENGL_EGL
> > > > +	help
> > > > +	  Driver for Broadcom VC6 (rpi4) GPUs (needs kmsro and vc4).
> > >
> > > I don't understand why you added that '(needs kmsro and vc4)': the
> > > corresponding config entries are properly selected above, and thus
> > > this part of the help text is of no use for the user, and tend to in
> >
> > kmsro/vc4 would mean BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_KMSRO (not mixed up
> > with the selected BR2_PACKAGE_MESA3D_GALLIUM_KMSRO) and
> > BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4 (not mixed up with the selected
> > BR2_PACKAGE_LIBDRM_VC4)...and all three mesa3d options (v3d, vc4, kmsro)
> > are needed to get a functional RPi4-64bit graphic output (see e.g. [1]:
> > The VC4 interface is via /dev/drm/card1. The V3D interface is via /dev/drm/card0.
> > All drawing commands go to V3D (aka card0). All screen resolution and configuration
> > commands go to VC4 (aka card1))...

Slo it means the code you provided is not complete! Why do you not
select the requried options?

    select BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_KMSRO
    select BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4

We don't want to let the user resolve the dependencies manually. This is
what the config options are for.

Currently, with the code you provided, this means that the following
defconfig would not generate a mesa3d that provperly supports the rpi4
(if I understood things correctly):

    BR2_arm=y
    BR2_cortex_a7=y
    BR2_TOOLCHAIN_EXTERNAL=y
    BR2_INIT_NONE=y
    BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV=y
    BR2_SYSTEM_BIN_SH_NONE=y
    # BR2_PACKAGE_BUSYBOX is not set
    BR2_PACKAGE_MESA3D=y
    BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D=y
    # BR2_PACKAGE_EUDEV_ENABLE_HWDB is not set
    # BR2_PACKAGE_IFUPDOWN_SCRIPTS is not set
    # BR2_TARGET_ROOTFS_TAR is not set

This is definitely not nice at all... :-(

Could you please fix that up?

Regards,
Yann E. MORIN.

> > > fact be very confusing. But since this is the same mess with the other
> > > options around, I left it. It would be nice to clean them away, though.
> > >
> > > > +	  It requires a recent enough mainline/raspberrypi kernel with
> > > > +	  drm v3d (CONFIG_DRM_V3D, CONFIG_DRM_VC4) support enabled.
> > >
> > > "recent enough" is of no use to the user: some woudl consider 4.0 to be
> > > recent, some would consider 5.0 to be old. Sol I replaced that with the
> > > exact version v3d was merged in mainline linux, that is 4.18.
> >
> > Thanks for looking up at which kernel version CONFIG_DRM_V3D was added...,
> > wanted to emphasize that both mainline and raspberrypi linux kernel
> > are supported (some years ago only the mainline kernel supported DRM_VC4
> > and/or 64-bit Rpi)...
> >
> > Regards,
> > Peter
> >
> > [1] https://forum.qt.io/topic/107764/drm-kms-configuration-for-raspberry-pi-4
> >
> > >
> > > Regards,
> > > Yann E. MORIN.
> > >
> > > > +
> > > >  config BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4
> > > >  	bool "Gallium vc4 driver"
> > > >  	depends on BR2_arm || BR2_aarch64
> > > > diff --git a/package/mesa3d/mesa3d.mk b/package/mesa3d/mesa3d.mk
> > > > index c7e5be55a0..1a18cf3c58 100644
> > > > --- a/package/mesa3d/mesa3d.mk
> > > > +++ b/package/mesa3d/mesa3d.mk
> > > > @@ -84,6 +84,7 @@ MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_RADEONSI) += radeonsi
> > > >  MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_SVGA)     += svga
> > > >  MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_SWRAST)   += swrast
> > > >  MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_TEGRA)    += tegra
> > > > +MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D)      += v3d
> > > >  MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4)      += vc4
> > > >  MESA3D_GALLIUM_DRIVERS-$(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VIRGL)    += virgl
> > > >  # DRI Drivers
> > > > @@ -162,6 +163,8 @@ endif
> > > >  MESA3D_PLATFORMS = surfaceless
> > > >  ifeq ($(BR2_PACKAGE_MESA3D_DRI_DRIVER),y)
> > > >  MESA3D_PLATFORMS += drm
> > > > +else ifeq ($(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D),y)
> > > > +MESA3D_PLATFORMS += drm
> > > >  else ifeq ($(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4),y)
> > > >  MESA3D_PLATFORMS += drm
> > > >  else ifeq ($(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_ETNAVIV),y)
> > > > --
> > > > 2.25.0
> > > >
> > > > _______________________________________________
> > > > buildroot mailing list
> > > > buildroot at busybox.net
> > > > http://lists.busybox.net/mailman/listinfo/buildroot
> > >
> >
> 

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