[3.16.y-ckt stable] Patch "drm: Fix return value of drm_framebuffer_init()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    drm: Fix return value of drm_framebuffer_init()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2b9b9d8f931819a735915651878d5468daca79b3 Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas at wunner.de>
Date: Thu, 15 Oct 2015 11:56:56 +0200
Subject: drm: Fix return value of drm_framebuffer_init()

commit 3c67d839b30c7d6d6ab5c6fddac0f58ec8095d50 upstream.

In its original version, drm_framebuffer_init() returned a negative int
if drm_mode_object_get() failed (f453ba046074, "DRM: add mode setting
support").

This was accidentally disabled by commit 4b096ac10da0 ("drm: revamp
locking around fb creation/destruction"). Thus, drm_framebuffer_init()
pretends success if drm_mode_object_get() failed.

Reinstate the original behaviour. Also fix erroneous kernel-doc of
drm_mode_object_get().

Fixes: 4b096ac10da0 ("drm: revamp locking around fb creation/
    destruction")
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Lukas Wunner <lukas at wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/drm_crtc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index ee96912e0824..0dd2c26c55ab 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -369,8 +369,7 @@ EXPORT_SYMBOL(drm_get_format_name);
  * reference counted modeset objects like framebuffers.
  *
  * Returns:
- * New unique (relative to other objects in @dev) integer identifier for the
- * object.
+ * Zero on success, error code on failure.
  */
 int drm_mode_object_get(struct drm_device *dev,
 			struct drm_mode_object *obj, uint32_t obj_type)
@@ -492,7 +491,7 @@ int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
 out:
 	mutex_unlock(&dev->mode_config.fb_lock);

-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(drm_framebuffer_init);