DPMS on Raspi Os Bookworm and Qt 6.8.1

[matzrm]

Hi,

my goal is control the power status of the attached monitor to enable/disable based on a power scheduling.

The problem is that when the QtApp is running with EGLFS_KMS as qpa platform it's created as a client master, so program as kmsblank can't connect to drm to control DPMS property.

So I tried to add the code in my QtApp ...

                   drmModePropertyPtr prop = drmModeGetProperty(drm_fd, connector->props[i]);
                    if (prop && QString::fromLocal8Bit(prop->name) == "DPMS") {
                        int nRet = drmModeConnectorSetProperty(drm_fd, connector->connector_id, prop->prop_id, dpmsMode);
                        qDebug()  << "Set DPMS "  << nRet;
                        drmModeFreeProperty(prop);
                        bRet = true;
                    }else{
                        drmModeFreeProperty(prop);
                    }

But the results is the same, because I can't open my drm card because is there a master.

So the question is...is there an Qt api or anoyher way to control monitor DPMS?

[matzrm]

I understand that only with Qt we can control DRM properties because it is the master and DRM can accepts only one master. But I don't need to implement any other drm interface, but I have to use qtplatform library, because they are speaking with drm.

So, investigating inside the code I have found a solution, but it use QPlatformScreen that is a Private Api:

add to cmake:

target_include_directories(appeturnix-qt6 PRIVATE
 ${qt_include_path}/QtGui/6.8.1/QtGui
)

and then you can use QPlatformScreen that is a private library...so...

QPlatformScreen *pScreen = screen->handle();
pScreen->setPowerState(QPlatformScreen::PowerStateOff);