nouveau: fix nv40_perfctr_next() cleanup regression

arndb · airlied · commit 86d65b7e7a0c · 2016-03-16T15:08:43.000+10:00
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: 8c1aeaa ("drm/nouveau/pm: cosmetic changes") Reviewed-by: Ben Skeggs <bskeggs@redhat.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git 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;
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -59,9 +59,11 @@ static void`
`59`	`59`	`nv40_perfctr_next(struct nvkm_pm pm, struct nvkm_perfdom dom)`
`60`	`60`	`{`
`61`	`61`	`struct nvkm_device *device = pm->engine.subdev.device;`
`62`		`- if (pm->sequence != pm->sequence) {`
	`62`	`+ struct nv40_pm *nv40pm = container_of(pm, struct nv40_pm, base);`
	`63`	`+`
	`64`	`+ if (nv40pm->sequence != pm->sequence) {`
`63`	`65`	`nvkm_wr32(device, 0x400084, 0x00000020);`
`64`		`- pm->sequence = pm->sequence;`
	`66`	`+ nv40pm->sequence = pm->sequence;`
`65`	`67`	`}`
`66`	`68`	`}`
`67`	`69`