Commit 658f4c82 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/devfreq: Add 1ms delay before clamping freq 



Add a short delay before clamping to idle frequency on active->idle
transition.  It takes ~0.5ms to increase the freq again on the next
idle->active transition, so this helps avoid extra freq transitions
on workloads that bounce between CPU and GPU.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20210927230455.1066297-2-robdclark@gmail.com


Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent ddb6e37a

drivers/gpu/drm/msm/msm_gpu.h

+7 −0
Original line number Diff line number Diff line
@@ -112,6 +112,13 @@ struct msm_gpu_devfreq { 
	 * it is inactive.

	 */

	unsigned long idle_freq;



	/**

	 * idle_work:

	 *

	 * Used to delay clamping to idle freq on active->idle transition.

	 */

	struct msm_hrtimer_work idle_work;

};



struct msm_gpu {

drivers/gpu/drm/msm/msm_gpu_devfreq.c

+30 −8
Original line number Diff line number Diff line
@@ -88,8 +88,12 @@ static struct devfreq_dev_profile msm_devfreq_profile = { 
	.get_cur_freq = msm_devfreq_get_cur_freq,

};



static void msm_devfreq_idle_work(struct kthread_work *work);



void msm_devfreq_init(struct msm_gpu *gpu)

{

	struct msm_gpu_devfreq *df = &gpu->devfreq;



	/* We need target support to do devfreq */

	if (!gpu->funcs->gpu_busy)

		return;
@@ -105,25 +109,27 @@ void msm_devfreq_init(struct msm_gpu *gpu) 
	msm_devfreq_profile.freq_table = NULL;

	msm_devfreq_profile.max_state = 0;



	gpu->devfreq.devfreq = devm_devfreq_add_device(&gpu->pdev->dev,

	df->devfreq = devm_devfreq_add_device(&gpu->pdev->dev,

			&msm_devfreq_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND,

			NULL);



	if (IS_ERR(gpu->devfreq.devfreq)) {

	if (IS_ERR(df->devfreq)) {

		DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize GPU devfreq\n");

		gpu->devfreq.devfreq = NULL;

		df->devfreq = NULL;

		return;

	}



	devfreq_suspend_device(gpu->devfreq.devfreq);

	devfreq_suspend_device(df->devfreq);



	gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node,

			gpu->devfreq.devfreq);

	gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node, df->devfreq);

	if (IS_ERR(gpu->cooling)) {

		DRM_DEV_ERROR(&gpu->pdev->dev,

				"Couldn't register GPU cooling device\n");

		gpu->cooling = NULL;

	}



	msm_hrtimer_work_init(&df->idle_work, gpu->worker, msm_devfreq_idle_work,

			      CLOCK_MONOTONIC, HRTIMER_MODE_REL);

}



void msm_devfreq_cleanup(struct msm_gpu *gpu)
@@ -154,6 +160,11 @@ void msm_devfreq_active(struct msm_gpu *gpu) 
	if (!df->devfreq)

		return;



	/*

	 * Cancel any pending transition to idle frequency:

	 */

	hrtimer_cancel(&df->idle_work.timer);



	/*

	 * Hold devfreq lock to synchronize with get_dev_status()/

	 * target() callbacks
@@ -184,9 +195,12 @@ void msm_devfreq_active(struct msm_gpu *gpu) 
	mutex_unlock(&df->devfreq->lock);

}



void msm_devfreq_idle(struct msm_gpu *gpu)



static void msm_devfreq_idle_work(struct kthread_work *work)

{

	struct msm_gpu_devfreq *df = &gpu->devfreq;

	struct msm_gpu_devfreq *df = container_of(work,

			struct msm_gpu_devfreq, idle_work.work);

	struct msm_gpu *gpu = container_of(df, struct msm_gpu, devfreq);

	unsigned long idle_freq, target_freq = 0;



	if (!df->devfreq)
@@ -207,3 +221,11 @@ void msm_devfreq_idle(struct msm_gpu *gpu) 


	mutex_unlock(&df->devfreq->lock);

}



void msm_devfreq_idle(struct msm_gpu *gpu)

{

	struct msm_gpu_devfreq *df = &gpu->devfreq;



	msm_hrtimer_queue_work(&df->idle_work, ms_to_ktime(1),

			       HRTIMER_MODE_ABS);

}