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>

4 files changed, 113 insertions, 5 deletions

diff --git a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
index 59ed7620fc1a..e6cb2bc40ebe 100644
--- a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
@@ -395,9 +395,15 @@ static const unsigned int a3xx_registers[] = {
 #ifdef CONFIG_DEBUG_FS
 static void a3xx_show(struct msm_gpu *gpu, struct seq_file *m)
 {
+        struct drm_device *dev = gpu->dev;
         int i;
 
         adreno_show(gpu, m);
+
+        mutex_lock(&dev->struct_mutex);
+
+        gpu->funcs->pm_resume(gpu);
+
         seq_printf(m, "status:   %08x\n",
                         gpu_read(gpu, REG_A3XX_RBBM_STATUS));
 
@@ -413,6 +419,10 @@ static void a3xx_show(struct msm_gpu *gpu, struct seq_file *m)
                         seq_printf(m, "IO:R %08x %08x\n", addr<<2, val);
                 }
         }
+
+        gpu->funcs->pm_suspend(gpu);
+
+        mutex_unlock(&dev->struct_mutex);
 }
 #endif
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index e6adafc7eff3..e913efa4ea0a 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -311,7 +311,6 @@ static void load_gpu(struct drm_device *dev)
                 gpu = NULL;
                 /* not fatal */
         }
-        mutex_unlock(&dev->struct_mutex);
 
         if (gpu) {
                 int ret;
@@ -321,10 +320,16 @@ static void load_gpu(struct drm_device *dev)
                         dev_err(dev->dev, "gpu hw init failed: %d\n", ret);
                         gpu->funcs->destroy(gpu);
                         gpu = NULL;
+                } else {
+                        /* give inactive pm a chance to kick in: */
+                        msm_gpu_retire(gpu);
                 }
+
         }
 
         priv->gpu = gpu;
+
+        mutex_unlock(&dev->struct_mutex);
 }
 
 static int msm_open(struct drm_device *dev, struct drm_file *file)
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);
 
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));