[3.11.y.z extended stable] Patch "drm/tegra: Remove gratuitous pad field" 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/tegra: Remove gratuitous pad field

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

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

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 61284b9d4c6e04fb76cf387bc52ea0c39913141c Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding at nvidia.com>
Date: Wed, 9 Apr 2014 14:26:59 +0200
Subject: drm/tegra: Remove gratuitous pad field

commit cbfbbabb89b37f6bad05f478d906a385149f288d upstream.

The version of the drm_tegra_submit structure that was merged all the
way back in 3.10 contains a pad field that was originally intended to
properly pad the following __u64 field. Unfortunately it seems like a
different field was dropped during review that caused this padding to
become unnecessary, but the pad field wasn't removed at that time.

One possible side-effect of this is that since the __u64 following the
pad is now no longer properly aligned, the compiler may (or may not)
introduce padding itself, which results in no predictable ABI.

Rectify this by removing the pad field so that all fields are again
naturally aligned. Technically this is breaking existing userspace ABI,
but given that there aren't any (released) userspace drivers that make
use of this yet, the fallout should be minimal.

Fixes: d43f81cbaf43 ("drm/tegra: Add gr2d device")
Signed-off-by: Thierry Reding <treding at nvidia.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 include/uapi/drm/tegra_drm.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/uapi/drm/tegra_drm.h b/include/uapi/drm/tegra_drm.h
index 73bde4e..da10687 100644
--- a/include/uapi/drm/tegra_drm.h
+++ b/include/uapi/drm/tegra_drm.h
@@ -105,7 +105,6 @@ struct drm_tegra_submit {
 	__u32 num_waitchks;
 	__u32 waitchk_mask;
 	__u32 timeout;
-	__u32 pad;
 	__u64 syncpts;
 	__u64 cmdbufs;
 	__u64 relocs;
--
1.9.1