From: Samuel Holland Date: Mon, 17 Feb 2020 06:09:06 +0000 (-0600) Subject: drm/sun4i: dsi: Avoid hotplug race with DRM driver bind X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=80579bf36c11a01c618d43ec6eb8056ef974c9cb;p=openwrt%2Fstaging%2Fblogic.git drm/sun4i: dsi: Avoid hotplug race with DRM driver bind 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 Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20200217060906.15152-1-samuel@sholland.org --- diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index b7174d515188..059939789730 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;