Re: [PATCH v3 3/3] drm/tiny: ili9486: remove conflicting framebuffers
From: Carlo Caione
Date: Tue Dec 06 2022 - 08:01:50 EST
On 06/12/2022 10:52, Thomas Zimmermann wrote:
Conflicting framebuffer on the SPI display ? How is that possible ?
Calling drm_aperture_remove_framebuffers() is only required if the
graphics card may have been pre-initialized by the system, such as a
VGA-compatible card on a PC.
Could the SPI display have been initialized by the firmware? If not, the
call should be left out.
What's happening on this board is that the builtin simpledrm driver is
creating fb0 backed by the framebuffer prepared by u-boot / grub, and
this the framebuffer being used by fbcon at early boot.
When the ILI9486 DRM driver is probed later during boot a second
framebuffer is created (fb1) and when fb0 is destroyed, fbcon still
remains attached to a non-existent framebuffer, so the user is left in
the dark.
What this patch is doing is that when the ILI driver is probed, fb0 is
destroyed and a new DRM-backed fb0 is created by the ILI DRM driver that
can be used by fbcon, so the user can correctly see the console on the
SPI display.
Cheers,
--
Carlo Caione