[Buildroot] [PATCH v2] qt5base: Qt KMS support does not depend on opengl

[Buildroot] [PATCH v2] qt5base: Qt KMS support does not depend on opengl

[Joshua Henderson]

Qt KMS support should not explicitly depend on the availability of opengl.
Don't explicitly disable KMS if opengl is not available and fallback to
detecting if libdrm is available before disabling kms.

The scenario where this is necessary involves using the Qt linuxfb backend
"dumb buffer" support via the DRM API.  This is new in Qt 5.9 [1] and only
requires KMS, but not opengl.

[1] http://doc.qt.io/qt-5/embedded-linux.html#linuxfb

Cc: Peter Seiderer <ps.report@gmx.net>
Cc: Julien Corjon <corjon.j@ecagroup.com>
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>

---

v2:
- If libdrm is configured, make it an explicit dependency.
---
 package/qt5/qt5base/qt5base.mk | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/package/qt5/qt5base/qt5base.mk b/package/qt5/qt5base/qt5base.mk
index 0ca11a5..7234948 100644
--- a/package/qt5/qt5base/qt5base.mk
+++ b/package/qt5/qt5base/qt5base.mk
@@ -40,8 +40,13 @@ ifeq ($(BR2_PACKAGE_MESA3D_OPENGL_EGL),y)
 QT5BASE_CONFIGURE_OPTS += -kms -gbm
 QT5BASE_DEPENDENCIES += mesa3d
 else
+ifeq ($(BR2_PACKAGE_LIBDRM),y)
+QT5BASE_CONFIGURE_OPTS += -kms
+QT5BASE_DEPENDENCIES += libdrm
+else
 QT5BASE_CONFIGURE_OPTS += -no-kms
 endif
+endif
 
 ifeq ($(BR2_ENABLE_DEBUG),y)
 QT5BASE_CONFIGURE_OPTS += -debug
-- 
2.7.4

[Buildroot] [PATCH v2] qt5base: Qt KMS support does not depend on opengl

[Thomas Petazzoni]

Hello,

On Mon, 18 Sep 2017 12:21:25 -0700, Joshua Henderson wrote:

> diff --git a/package/qt5/qt5base/qt5base.mk b/package/qt5/qt5base/qt5base.mk
> index 0ca11a5..7234948 100644
> --- a/package/qt5/qt5base/qt5base.mk
> +++ b/package/qt5/qt5base/qt5base.mk
> @@ -40,8 +40,13 @@ ifeq ($(BR2_PACKAGE_MESA3D_OPENGL_EGL),y)
>  QT5BASE_CONFIGURE_OPTS += -kms -gbm
>  QT5BASE_DEPENDENCIES += mesa3d
>  else
> +ifeq ($(BR2_PACKAGE_LIBDRM),y)
> +QT5BASE_CONFIGURE_OPTS += -kms
> +QT5BASE_DEPENDENCIES += libdrm
> +else
>  QT5BASE_CONFIGURE_OPTS += -no-kms
>  endif
> +endif

It looks good in principle, but these conditions become very messy. Can
we do something like this instead:

ifeq ($(BR2_PACKAGE_LIBDRM),y)
QT5BASE_CONFIGURE_OPTS += -kms
QT5BASE_DEPENDENCIES += libdrm
else
QT5BASE_CONFIGURE_OPTS += -no-kms
endif

ifeq ($($(BR2_PACKAGE_MESA3D_OPENGL_EGL),y)
QT5BASE_CONFIGURE_OPTS += -gbm
QT5BASE_DEPENDENCIES += mesa3d
else
QT5BASE_CONFIGURE_OPTS += -no-gbm
endif

It should be functionally the same, because when
BR2_PACKAGE_MESA3D_OPENGL_EGL=y, BR2_PACKAGE_LIBDRM is always enabled I
believe.

Could you test this, and send an updated version if it works?

Thanks a lot!

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com