On Fri, Oct 22, 2021 at 04:40:40PM +0200, Javier Martinez Canillas wrote:
The simpledrm driver allows to use the frame buffer that was set-up by the firmware. This gives early video output before the platform DRM driver is probed and takes over.
But it would be useful to have a way to disable this take over by the real DRM drivers. For example, there may be bugs in the DRM drivers that could cause the display output to not work correctly.
For those cases, it would be good to keep the simpledrm driver instead and at least get a working display as set-up by the firmware.
Let's add a drm.remove_fb boolean kernel command line parameter, that when set to false will prevent the conflicting framebuffers to being removed.
Since the drivers call drm_aperture_remove_conflicting_framebuffers() very early in their probe callback, this will cause the drivers' probe to fail.
Why is that better than just modprobe.blacklisting those drivers?