linux-kernel - Re: [PATCH v3 5/5] drm/arm/malidp: Added the late system pm functions

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Date:   Wed, 25 Apr 2018 09:17:22 +0200
From:   Daniel Vetter <daniel@...ll.ch>
To:     Ayan Kumar Halder <ayan.halder@....com>
Cc:     liviu.dudau@....com, brian.starkey@....com, malidp@...s.arm.com,
        airlied@...ux.ie, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, nd@....com
Subject: Re: [PATCH v3 5/5] drm/arm/malidp: Added the late system pm functions

On Tue, Apr 24, 2018 at 07:12:47PM +0100, Ayan Kumar Halder wrote:
> malidp_pm_suspend_late checks if the runtime status is not suspended
> and if so, invokes malidp_runtime_pm_suspend which disables the
> display engine/core interrupts and the clocks. It sets the runtime status
> as suspended.
> 
> The difference between suspend() and suspend_late() is as follows:-
> 1. suspend() makes the device quiescent. In our case, we invoke the DRM
> helper which disables the CRTC. This would have invoked runtime pm
> suspend but the system suspend process disables runtime pm.
> 2. suspend_late() It continues the suspend operations of the drm device 
> which was started by suspend(). In our case, it performs the same functionality
> as runtime_suspend().
> 
> The complimentary functions are resume() and resume_early(). In the case of
> resume_early(), we invoke malidp_runtime_pm_resume() which enables the clocks
> and the interrupts. It sets the runtime status as active. If the device was
> in runtime suspend mode before system suspend was called, pm_runtime_work()
> will put the device back in runtime suspended mode( after the complete system
> has been resumed).
> 
> Signed-off-by: Ayan Kumar Halder <ayan.halder@....com>
> 

Afaiui we still haven't bottomed out on the discussion on v1. Did you get
hold of Rafael?
-Daniel

> ---
> Changes in v3:-
> - Rebased on top of earlier v3 patches, 
> 
> Changes in v2:-
> - Removed the change id and modified the commit message
> ---
>  drivers/gpu/drm/arm/malidp_drv.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
> index 82221ea..c53b46a 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.c
> +++ b/drivers/gpu/drm/arm/malidp_drv.c
> @@ -768,8 +768,25 @@ static int __maybe_unused malidp_pm_resume(struct device *dev)
>  	return 0;
>  }
>  
> +static int __maybe_unused malidp_pm_suspend_late(struct device *dev)
> +{
> +	if (!pm_runtime_status_suspended(dev)) {
> +		malidp_runtime_pm_suspend(dev);
> +		pm_runtime_set_suspended(dev);
> +	}
> +	return 0;
> +}
> +
> +static int __maybe_unused malidp_pm_resume_early(struct device *dev)
> +{
> +	malidp_runtime_pm_resume(dev);
> +	pm_runtime_set_active(dev);
> +	return 0;
> +}
> +
>  static const struct dev_pm_ops malidp_pm_ops = {
>  	SET_SYSTEM_SLEEP_PM_OPS(malidp_pm_suspend, malidp_pm_resume) \
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(malidp_pm_suspend_late, malidp_pm_resume_early) \
>  	SET_RUNTIME_PM_OPS(malidp_runtime_pm_suspend, malidp_runtime_pm_resume, NULL)
>  };
>  
> -- 
> 2.7.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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