On Tue, 12 Apr 2022 at 11:14, Piotr Oniszczuk <piotr.oniszczuk@xxxxxxxxx> wrote: > > Wiadomość napisana przez Lucas Stach <l.stach@xxxxxxxxxxxxxx> w dniu 12.04.2022, o godz. 10:10: > > 1. The application feeds a wrong modifier list to the GBM > > implementation, as it may have queried another plane in the assumption > > that supported modifiers are uniform across all planes. > > This will be cardinal design error. > (keeping in mind we have multiple producers (GPU/video decoder) and multiple consumers (base & overlay DRM planes) > > > > 2. The GBM implementation (Panfrost) actually allocates a surface > > instead of failing the allocation, even if it does not support any > > combination of the provided format and modifier list. > > Testing Sacha patch (see today's email from Sascha) i'm getting > > Qt: EGL Error : Could not create the egl surface: error = 0x3009 > > i'm reading this as: Qt tries allocate EGL surface and EGL returns error. > or i'm wrong? Correct, that's EGL_BAD_MATCH. There are very few ways that can happen; by far the most likely is that Qt has chosen an EGLConfig which does not correctly correspond to the format. (If it was an impossible format/modifier combination, then this would be already caught when allocating the gbm_surface.) Either way, it seems quite clear that the VOP2 driver is totally fine here, and that you have a Qt (likely) or Mesa (tbh less likely) issue to debug to get the app working. Cheers, Daniel