drm/msm: crank down gpu when inactive

Shut down the clks when the gpu has nothing to do.  A short inactivity
timer is used to provide a low pass filter for power transitions.

Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 82 insertions, 3 deletions

diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 0cfe3f426ee4..3e667ca1f2b9 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -154,9 +154,18 @@ static int disable_axi(struct msm_gpu *gpu)
 
 int msm_gpu_pm_resume(struct msm_gpu *gpu)
 {
+	struct drm_device *dev = gpu->dev;
 	int ret;
 
-	DBG("%s", gpu->name);
+	DBG("%s: active_cnt=%d", gpu->name, gpu->active_cnt);
+
+	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
+	if (gpu->active_cnt++ > 0)
+		return 0;
+
+	if (WARN_ON(gpu->active_cnt <= 0))
+		return -EINVAL;
 
 	ret = enable_pwrrail(gpu);
 	if (ret)
@@ -175,9 +184,18 @@ int msm_gpu_pm_resume(struct msm_gpu *gpu)
 
 int msm_gpu_pm_suspend(struct msm_gpu *gpu)
 {
+	struct drm_device *dev = gpu->dev;
 	int ret;
 
-	DBG("%s", gpu->name);
+	DBG("%s: active_cnt=%d", gpu->name, gpu->active_cnt);
+
+	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
+	if (--gpu->active_cnt > 0)
+		return 0;
+
+	if (WARN_ON(gpu->active_cnt < 0))
+		return -EINVAL;
 
 	ret = disable_axi(gpu);
 	if (ret)
@@ -195,6 +213,55 @@ int msm_gpu_pm_suspend(struct msm_gpu *gpu)
 }
 
 /*
+ * Inactivity detection (for suspend):
+ */
+
+static void inactive_worker(struct work_struct *work)
+{
+	struct msm_gpu *gpu = container_of(work, struct msm_gpu, inactive_work);
+	struct drm_device *dev = gpu->dev;
+
+	if (gpu->inactive)
+		return;
+
+	DBG("%s: inactive!\n", gpu->name);
+	mutex_lock(&dev->struct_mutex);
+	if (!(msm_gpu_active(gpu) || gpu->inactive)) {
+		disable_axi(gpu);
+		disable_clk(gpu);
+		gpu->inactive = true;
+	}
+	mutex_unlock(&dev->struct_mutex);
+}
+
+static void inactive_handler(unsigned long data)
+{
+	struct msm_gpu *gpu = (struct msm_gpu *)data;
+	struct msm_drm_private *priv = gpu->dev->dev_private;
+
+	queue_work(priv->wq, &gpu->inactive_work);
+}
+
+/* cancel inactive timer and make sure we are awake: */
+static void inactive_cancel(struct msm_gpu *gpu)
+{
+	DBG("%s", gpu->name);
+	del_timer(&gpu->inactive_timer);
+	if (gpu->inactive) {
+		enable_clk(gpu);
+		enable_axi(gpu);
+		gpu->inactive = false;
+	}
+}
+
+static void inactive_start(struct msm_gpu *gpu)
+{
+	DBG("%s", gpu->name);
+	mod_timer(&gpu->inactive_timer,
+			round_jiffies_up(jiffies + DRM_MSM_INACTIVE_JIFFIES));
+}
+
+/*
  * Hangcheck detection for locked gpu:
  */
 
@@ -206,7 +273,10 @@ static void recover_worker(struct work_struct *work)
 	dev_err(dev->dev, "%s: hangcheck recover!\n", gpu->name);
 
 	mutex_lock(&dev->struct_mutex);
-	gpu->funcs->recover(gpu);
+	if (msm_gpu_active(gpu)) {
+		inactive_cancel(gpu);
+		gpu->funcs->recover(gpu);
+	}
 	mutex_unlock(&dev->struct_mutex);
 
 	msm_gpu_retire(gpu);
@@ -281,6 +351,9 @@ static void retire_worker(struct work_struct *work)
 	}
 
 	mutex_unlock(&dev->struct_mutex);
+
+	if (!msm_gpu_active(gpu))
+		inactive_start(gpu);
 }
 
 /* call from irq handler to schedule work to retire bo's */
@@ -302,6 +375,8 @@ int msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
 
 	gpu->submitted_fence = submit->fence;
 
+	inactive_cancel(gpu);
+
 	ret = gpu->funcs->submit(gpu, submit, ctx);
 	priv->lastctx = ctx;
 
@@ -357,11 +432,15 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 	gpu->dev = drm;
 	gpu->funcs = funcs;
 	gpu->name = name;
+	gpu->inactive = true;
 
 	INIT_LIST_HEAD(&gpu->active_list);
 	INIT_WORK(&gpu->retire_work, retire_worker);
+	INIT_WORK(&gpu->inactive_work, inactive_worker);
 	INIT_WORK(&gpu->recover_work, recover_worker);
 
+	setup_timer(&gpu->inactive_timer, inactive_handler,
+			(unsigned long)gpu);
 	setup_timer(&gpu->hangcheck_timer, hangcheck_handler,
 			(unsigned long)gpu);