drm/fb-helper: generic: Call drm_client_add() after setup is done

[ Upstream commit 6e3f17ee73f7e3c2ef0e2c8fd8624b2ece8ef2c9 ]

Hotplug can happen while drm_fbdev_generic_setup() is running so move
drm_client_add() call after setup is done to avoid
drm_fbdev_client_hotplug() running in two threads at the same time.

Fixes: 9060d7f49376 ("drm/fb-helper: Finish the generic fbdev emulation")
Cc: stable@vger.kernel.org
Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190401141358.25309-1-noralf@tronnes.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 1c87ad6667e73f85901ed476ade786a37121748b..da9a381d6b577d7813d72cd0db989f98ce8c90ff 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -3257,8 +3257,6 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
                return ret;
        }
 
-       drm_client_add(&fb_helper->client);
-
        if (!preferred_bpp)
                preferred_bpp = dev->mode_config.preferred_depth;
        if (!preferred_bpp)
@@ -3267,6 +3265,8 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
 
        drm_fbdev_client_hotplug(&fb_helper->client);
 
+       drm_client_add(&fb_helper->client);
+
        return 0;
 }
 EXPORT_SYMBOL(drm_fbdev_generic_setup);