MobileRead Forums - View Single Post - Sigil-2.5.1 Released

KevinH · 06-02-2025, 01:47 PM

Here is why gbm mode is disabled on nvidia gpus because of the following (according to Qt sources):

https://download.nvidia.com/XFree86/...EADME/kms.html

Notice the known issues at the end which says nvidia's gbm support does not allow texture buffers to be uploaded to the kernel kms module.

Not sure if those nvidia docs are up to date or not.

See this commit to Qt WebEngine:

https://github.com/qt/qtwebengine/co...bc934cf19b2f07

At least there is a env var QTWEBENGINE_FORCE_USE_GBM you can set to 1 to override things.

It sounds like Vulkan support is the way forward with Qt and nvidia.

06-02-2025, 01:47 PM	#33
KevinH Sigil Developer Posts: 8,893 Karma: 6120478 Join Date: Nov 2009 Device: many	Here is why gbm mode is disabled on nvidia gpus because of the following (according to Qt sources): https://download.nvidia.com/XFree86/...EADME/kms.html Notice the known issues at the end which says nvidia's gbm support does not allow texture buffers to be uploaded to the kernel kms module. Not sure if those nvidia docs are up to date or not. See this commit to Qt WebEngine: https://github.com/qt/qtwebengine/co...bc934cf19b2f07 At least there is a env var QTWEBENGINE_FORCE_USE_GBM you can set to 1 to override things. It sounds like Vulkan support is the way forward with Qt and nvidia. Last edited by KevinH; 06-02-2025 at 01:52 PM.