From 80579bf36c11a01c618d43ec6eb8056ef974c9cb Mon Sep 17 00:00:00 2001
From: Samuel Holland <samuel@sholland.org>
Date: Mon, 17 Feb 2020 00:09:06 -0600
Subject: drm/sun4i: dsi: Avoid hotplug race with DRM driver bind
Git-commit: 80579bf36c11a01c618d43ec6eb8056ef974c9cb
Patch-mainline: v5.7-rc1
References: bsc#1113956
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>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200217060906.15152-1-samuel@sholland.org
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
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 b7174d5151881c..059939789730d8 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;
--
2.26.0