FAILED: patch "[PATCH] drm/fb-helper: generic: Call drm_client_add() after setup is" failed to apply to 4.19-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6e3f17ee73f7e3c2ef0e2c8fd8624b2ece8ef2c9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
Date: Mon, 1 Apr 2019 16:13:58 +0200
Subject: [PATCH] drm/fb-helper: generic: Call drm_client_add() after setup is
 done
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 0d8384e30e16..84791dd4a90d 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -3312,8 +3312,6 @@ 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)
@@ -3324,6 +3322,8 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
 	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);