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, 15 insertions, 1 deletions

diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 458db8c64c28..fad27008922f 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -72,6 +72,10 @@ struct msm_gpu {
 
 	uint32_t submitted_fence;
 
+	/* is gpu powered/active? */
+	int active_cnt;
+	bool inactive;
+
 	/* worker for handling active-list retiring: */
 	struct work_struct retire_work;
 
@@ -91,7 +95,12 @@ struct msm_gpu {
 	uint32_t bsc;
 #endif
 
-	/* Hang Detction: */
+	/* Hang and Inactivity Detection:
+	 */
+#define DRM_MSM_INACTIVE_PERIOD   66 /* in ms (roughly four frames) */
+#define DRM_MSM_INACTIVE_JIFFIES  msecs_to_jiffies(DRM_MSM_INACTIVE_PERIOD)
+	struct timer_list inactive_timer;
+	struct work_struct inactive_work;
 #define DRM_MSM_HANGCHECK_PERIOD 500 /* in ms */
 #define DRM_MSM_HANGCHECK_JIFFIES msecs_to_jiffies(DRM_MSM_HANGCHECK_PERIOD)
 	struct timer_list hangcheck_timer;
@@ -99,6 +108,11 @@ struct msm_gpu {
 	struct work_struct recover_work;
 };
 
+static inline bool msm_gpu_active(struct msm_gpu *gpu)
+{
+	return gpu->submitted_fence > gpu->funcs->last_fence(gpu);
+}
+
 static inline void gpu_write(struct msm_gpu *gpu, u32 reg, u32 data)
 {
 	msm_writel(data, gpu->mmio + (reg << 2));