[PATCH 5.1 78/85] drm/fb-helper: generic: Call drm_client_add() after setup is done

[Greg Kroah-Hartman]

From: Noralf Trønnes <nor...@tronnes.org>

commit 6e3f17ee73f7e3c2ef0e2c8fd8624b2ece8ef2c9 upstream.

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: sta...@vger.kernel.org
Reported-by: Daniel Vetter <daniel.vet...@ffwll.ch>
Signed-off-by: Noralf Trønnes <nor...@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
Link: 
https://patchwork.freedesktop.org/patch/msgid/20190401141358.25309-1-nor...@tronnes.org
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/gpu/drm/drm_fb_helper.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -3317,8 +3317,6 @@ int drm_fbdev_generic_setup(struct drm_d
                return ret;
        }
 
-       drm_client_add(&fb_helper->client);
-
        if (!preferred_bpp)
                preferred_bpp = dev->mode_config.preferred_depth;
        if (!preferred_bpp)
@@ -3329,6 +3327,8 @@ int drm_fbdev_generic_setup(struct drm_d
        if (ret)
                DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
 
+       drm_client_add(&fb_helper->client);
+
        return 0;
 }
 EXPORT_SYMBOL(drm_fbdev_generic_setup);