We need to make sure that the DRM driver is fully registered before allowing the panel to be attached. Otherwise, we may trigger a hotplug event before sun4i_framebuffer_init() sets up drm->mode_config.funcs, causing a NULL pointer dereference.

Fixes: 1a2703bd7356 ("drm/sun4i: dsi: Allow binding the host without a panel") Signed-off-by: Samuel Holland samuel@sholland.org ---

This fixes a bug in my previous patch series, that I didn't catch until it was already merged.

--- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 9aa78c73873c..9cc1bb69fcda 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -970,7 +970,7 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,

if (IS_ERR(panel)) return PTR_ERR(panel); - if (!dsi->drm) + if (!dsi->drm || !dsi->drm->registered) return -EPROBE_DEFER;

dsi->panel = panel;