Re: [PATCH 4/7] drm/msm: crank down gpu when inactive

On 03/10/2014 10:47 AM, Rob Clark wrote:

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.

Good luck. Power management will take years off your life.

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

Acked-by: Jordan Crouse jcrouse@codeaurora.org

---

drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 10 +++++ drivers/gpu/drm/msm/msm_drv.c | 7 ++- drivers/gpu/drm/msm/msm_gpu.c | 85 +++++++++++++++++++++++++++++++++-- drivers/gpu/drm/msm/msm_gpu.h | 16 ++++++- 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 59ed762..e6cb2bc 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 e6adafc..e913efa 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 0cfe3f4..3e667ca 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 458db8c..fad2700 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));