[Buildroot] Build failure with Vivante and QT5 w/ eglfs

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Fri, 4 Mar 2016 14:10:58 +0100, Gary Bisson wrote:

> Well my thought process was that it was kind of forbidden to modify
> the qtbase package for a i.MX-specific corner case.
> 
> So I tried to force it in imx-gpu-viv to use fb depending on
> BR2_PACKAGE_QT5BASE_EGLFS but it only brought those recursive issues.

You indeed can't do this, as it creates a circular dependency.

> Well if we are allowed to modify qtbase I guess it would be way
> easier. Would something like this be acceptable?
> index 64a7f65..aa54b3e 100644
> --- a/package/qt5/qt5base/Config.in
> +++ b/package/qt5/qt5base/Config.in
> @@ -201,10 +201,14 @@ config BR2_PACKAGE_QT5BASE_EGLFS
>         select BR2_PACKAGE_QT5BASE_OPENGL
>         depends on BR2_PACKAGE_HAS_LIBEGL
>         depends on BR2_PACKAGE_QT5_GL_AVAILABLE
> +       depends on !BR2_PACKAGE_IMX_GPU_VIV_OUTPUT_X11
> 
>  comment "eglfs backend available if OpenGL and EGL are enabled"
>         depends on !BR2_PACKAGE_HAS_LIBEGL || !BR2_PACKAGE_QT5_GL_AVAILABLE
> 
> +comment "eglfs backend not available for X11 version of i.MX 3D libraries"
> +       depends on BR2_PACKAGE_IMX_GPU_VIV_OUTPUT_X11
> +

No this is not good, because there are other OpenGL implementations
than imx-gpu-viv. So at the very least, you would need something like
the below. I also believe it makes more sense to use positive
condition, i.e express a dependency on the FB output, rather than a
dependency on not having the X11 output.

	# If the imx-gpu-viv implementation is used, we need its FB variant
	depends on !BR2_PACKAGE_IMX_GPU_VIV || BR2_PACKAGE_IMX_GPU_VIV_OUTPUT_FB

comment "eglfs backend needs the FB output of i.MX GPU libraries"
	depends on BR2_PACKAGE_IMX_GPU_VIV && !BR2_PACKAGE_IMX_GPU_VIV_OUTPUT_FB

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com