Patch "nouveau: fix nv40_perfctr_next() cleanup regression" has been added to the 4.4-stable tree

Patch "nouveau: fix nv40_perfctr_next() cleanup regression" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    nouveau: fix nv40_perfctr_next() cleanup regression

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nouveau-fix-nv40_perfctr_next-cleanup-regression.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 86d65b7e7a0c927d07d18605c276d0f142438ead Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 14 Mar 2016 15:24:10 +0100
Subject: nouveau: fix nv40_perfctr_next() cleanup regression

From: Arnd Bergmann <arnd@arndb.de>

commit 86d65b7e7a0c927d07d18605c276d0f142438ead upstream.

gcc-6 warns about code in the nouveau driver that is obviously silly:

drivers/gpu/drm/nouveau/nvkm/engine/pm/nv40.c: In function 'nv40_perfctr_next':
drivers/gpu/drm/nouveau/nvkm/engine/pm/nv40.c:62:19: warning: self-comparison always evaluats to false [-Wtautological-compare]
  if (pm->sequence != pm->sequence) {

The behavior was accidentally introduced in a patch described as "This is
purely preparation for upcoming commits, there should be no code changes here.".
As far as I can tell, that was true for the rest of that patch except for
this one function, which has been changed to a NOP.

This patch restores the original behavior.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 8c1aeaa13954 ("drm/nouveau/pm: cosmetic changes")
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/nouveau/nvkm/engine/pm/nv40.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/nv40.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/nv40.c
@@ -59,9 +59,11 @@ static void
 nv40_perfctr_next(struct nvkm_pm *pm, struct nvkm_perfdom *dom)
 {
 	struct nvkm_device *device = pm->engine.subdev.device;
-	if (pm->sequence != pm->sequence) {
+	struct nv40_pm *nv40pm = container_of(pm, struct nv40_pm, base);
+
+	if (nv40pm->sequence != pm->sequence) {
 		nvkm_wr32(device, 0x400084, 0x00000020);
-		pm->sequence = pm->sequence;
+		nv40pm->sequence = pm->sequence;
 	}
 }
 


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-4.4/include-linux-kernel.h-change-abs-macro-so-it-uses-consistent-return-type.patch
queue-4.4/ath9k-fix-misleading-indentation.patch
queue-4.4/iwlegacy-avoid-warning-about-missing-braces.patch
queue-4.4/kbuild-disable-maybe-uninitialized-warning-for-config_profile_all_branches.patch
queue-4.4/net-caif-fix-misleading-indentation.patch
queue-4.4/nouveau-fix-nv40_perfctr_next-cleanup-regression.patch
queue-4.4/gcov-disable-wmaybe-uninitialized-warning.patch
queue-4.4/am437x-vfpe-fix-typo-in-vpfe_get_app_input_index.patch
queue-4.4/fix-build-warning-in-kernel-cpuset.c.patch
queue-4.4/reiserfs-fix-new_insert_key-may-be-used-uninitialized.patch