drm/amdgpu: restore original stable pstate on ctx fini

Save the original stable pstate on ctx init and restore
it on ctx fini so that we restore a manually selected
stable pstate on ctx exit.

v2: fix init order (Alex)
v3: don't add new variable to ctx struct (Evan)

Fixes: c65b364c ("drm/amdgpu/ctx: only reset stable pstate if the user changed it (v2)")
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c

@@ -272,32 +272,6 @@ static ktime_t amdgpu_ctx_fini_entity(struct amdgpu_ctx_entity *entity)
 	return res;
 }
 
-static int amdgpu_ctx_init(struct amdgpu_ctx_mgr *mgr, int32_t priority,
-			   struct drm_file *filp, struct amdgpu_ctx *ctx)
-{
-	int r;
-
-	r = amdgpu_ctx_priority_permit(filp, priority);
-	if (r)
-		return r;
-
-	memset(ctx, 0, sizeof(*ctx));
-
-	kref_init(&ctx->refcount);
-	ctx->mgr = mgr;
-	spin_lock_init(&ctx->ring_lock);
-	mutex_init(&ctx->lock);
-
-	ctx->reset_counter = atomic_read(&mgr->adev->gpu_reset_counter);
-	ctx->reset_counter_query = ctx->reset_counter;
-	ctx->vram_lost_counter = atomic_read(&mgr->adev->vram_lost_counter);
-	ctx->init_priority = priority;
-	ctx->override_priority = AMDGPU_CTX_PRIORITY_UNSET;
-	ctx->stable_pstate = AMDGPU_CTX_STABLE_PSTATE_NONE;
-
-	return 0;
-}
-
 static int amdgpu_ctx_get_stable_pstate(struct amdgpu_ctx *ctx,
 					u32 *stable_pstate)
 {
@@ -326,6 +300,38 @@ static int amdgpu_ctx_get_stable_pstate(struct amdgpu_ctx *ctx,
 	return 0;
 }
 
+static int amdgpu_ctx_init(struct amdgpu_ctx_mgr *mgr, int32_t priority,
+			   struct drm_file *filp, struct amdgpu_ctx *ctx)
+{
+	u32 current_stable_pstate;
+	int r;
+
+	r = amdgpu_ctx_priority_permit(filp, priority);
+	if (r)
+		return r;
+
+	memset(ctx, 0, sizeof(*ctx));
+
+	kref_init(&ctx->refcount);
+	ctx->mgr = mgr;
+	spin_lock_init(&ctx->ring_lock);
+	mutex_init(&ctx->lock);
+
+	ctx->reset_counter = atomic_read(&mgr->adev->gpu_reset_counter);
+	ctx->reset_counter_query = ctx->reset_counter;
+	ctx->vram_lost_counter = atomic_read(&mgr->adev->vram_lost_counter);
+	ctx->init_priority = priority;
+	ctx->override_priority = AMDGPU_CTX_PRIORITY_UNSET;
+
+	r = amdgpu_ctx_get_stable_pstate(ctx, &current_stable_pstate);
+	if (r)
+		return r;
+
+	ctx->stable_pstate = current_stable_pstate;
+
+	return 0;
+}
+
 static int amdgpu_ctx_set_stable_pstate(struct amdgpu_ctx *ctx,
 					u32 stable_pstate)
 {
@@ -397,7 +403,7 @@ static void amdgpu_ctx_fini(struct kref *ref)
 	}
 
 	if (drm_dev_enter(&adev->ddev, &idx)) {
-		amdgpu_ctx_set_stable_pstate(ctx, AMDGPU_CTX_STABLE_PSTATE_NONE);
+		amdgpu_ctx_set_stable_pstate(ctx, ctx->stable_pstate);
 		drm_dev_exit(idx);
 	}