Re: [meta-arago][master/scarthgap][PATCH] recipes-qt: qt5: Add xkbcommon to qtbase PACKAGECONFIG

[Denys Dmytriyenko <denis@denix.org>]

On Wed, Jun 05, 2024 at 12:39:12PM +0530, Chirag Shilwant via lists.yoctoproject.org wrote:
> Hi Denys & Ryan,
> 
> On 04/06/24 21:38, Denys Dmytriyenko wrote:
> >On Mon, Jun 03, 2024 at 02: 52: 55PM +0530, Chirag Shilwant via
> >lists. yoctoproject. org wrote: > From: Sai Sree Kartheek Adivi
> ><s-adivi@ ti. com> > > - For QT apps to use physical keyboard,
> >xkbcommon has to be added in > PACKAGECONFIG. 
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> >On Mon, Jun 03, 2024 at 02:52:55PM +0530, Chirag Shilwant via lists.yoctoproject.org wrote:
> >> From: Sai Sree Kartheek Adivi <s-adivi@ti.com>
> >> > - For QT apps to use physical keyboard, xkbcommon has to be
> >added in
> >> PACKAGECONFIG. This was supported until 09.01 using xkbcommon-evdev which at
> >> present is an invalid PACKAGECONFIG & hence was dropped from meta-arago [1].
> >> > - Hence, add xkbcommon to PACKAGECONFIG which will enable the
> >use of
> >> physical keyboard in QT apps.
> >> > [1]: https://git.ti.com/cgit/arago-project/meta-arago/commit/?h=scarthgap&id=de16946741249265a38acb7bb503b39a0c2b4175
> >> > Signed-off-by: Chirag Shilwant <c-shilwant@ti.com>
> >> ---
> >>  meta-arago-distro/recipes-qt/qt5/qtbase_%.bbappend | 2 ++
> >>  1 file changed, 2 insertions(+)
> >> > diff --git
> >a/meta-arago-distro/recipes-qt/qt5/qtbase_%.bbappend
> >b/meta-arago-distro/recipes-qt/qt5/qtbase_%.bbappend
> >> index b1205b5a..6f94c574 100644
> >> --- a/meta-arago-distro/recipes-qt/qt5/qtbase_%.bbappend
> >> +++ b/meta-arago-distro/recipes-qt/qt5/qtbase_%.bbappend
> >> @@ -4,6 +4,8 @@ GLES_EXTRA_DEPS = "libdrm wayland"
> >>  >  PACKAGECONFIG[gles2] = "-opengl es2 -eglfs,,virtual/libgles2
> >virtual/egl ${GLES_EXTRA_DEPS}"
> >>  > +PACKAGECONFIG:append:k3 = " xkbcommon"
> >
> >This would make the package machine-specific - why is it only applicable to k3?
> 
> 
> For non k3 based platforms, with the removal of Matrix GUI I don't see
> any QT Demos under meta-arago-demos which might need the keyboard
> functionality [Ryan correct me if we have any QT demo applicable for
> non k3 based platform which needs keyboard].
> 
> For k3 platforms, we have TI Apps Launcher (a QT based OOB demo) for which
> xkbcommon is needed & hence I made this change machine specific.

That is a wrong reason to make a large package that many other packages depend 
on (and build on top of) to be machine-specific! That will force qtbase to be 
rebuilt from scratch for each and every K3 platform, instead of re-using 
common Aarch64 binaries. Moreover, that invalidates sstate cache for all other 
packages that depend on qtbase, essentially making them machine-specific as 
well... In other words - keyboard support does not sound even remotely as a 
machine-specific feature, so should rather be enabled or disabled globally on 
a per-distro basis. And thus, should be set in distro config file.


> Btw, Denys do you have any background on why does meta-qt5 just in
> case of Wayland doesn't
> support this keyboard enablement by default though I see for x11
> they add 'xkbcommon' in
> PACKAGECONFIG by default [1]
> 
> [1]: https://github.com/meta-qt5/meta-qt5/blob/scarthgap/recipes-qt/qt5/qtbase_git.bb#L70

Wayland support in Qt5 is provided by its QtWayland module and it handles 
xkbcommon. Are there some corner cases you are trying to enable with this?

-- 
Denys