[PATCH] drm/meson: enable runtime PM

Kevin Hilman khilman at baylibre.com
Mon Sep 30 08:34:21 PDT 2019


Neil Armstrong <narmstrong at baylibre.com> writes:

> Hi Kevin,
>
> On 25/09/2019 21:31, Kevin Hilman wrote:
>> From: Kevin Hilman <khilman at baylibre.com>
>> 
>> On some SoCs, the VPU is in a power-domain and needs runtime PM
>> enabled and used in order to keep the power domain on.
>> 
>> Signed-off-by: Kevin Hilman <khilman at baylibre.com>
>> ---
>>  drivers/gpu/drm/meson/meson_drv.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
>> index 2310c96fff46..256b6a0e9c6b 100644
>> --- a/drivers/gpu/drm/meson/meson_drv.c
>> +++ b/drivers/gpu/drm/meson/meson_drv.c
>> @@ -14,6 +14,7 @@
>>  #include <linux/platform_device.h>
>>  #include <linux/component.h>
>>  #include <linux/of_graph.h>
>> +#include <linux/pm_runtime.h>
>>  
>>  #include <drm/drmP.h>
>>  #include <drm/drm_atomic.h>
>> @@ -274,6 +275,7 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>>  
>>  	/* Hardware Initialization */
>>  
>> +	pm_runtime_get_sync(dev);
>>  	meson_vpu_init(priv);
>>  	meson_venc_init(priv);
>>  	meson_vpp_init(priv);
>> @@ -416,6 +418,7 @@ static int meson_drv_probe(struct platform_device *pdev)
>>  	struct device_node *ep, *remote;
>>  	int count = 0;
>>  
>> +	pm_runtime_enable(&pdev->dev);
>>  	for_each_endpoint_of_node(np, ep) {
>>  		remote = of_graph_get_remote_port_parent(ep);
>>  		if (!remote || !of_device_is_available(remote)) {
>> @@ -440,6 +443,7 @@ static int meson_drv_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	/* If no output endpoints were available, simply bail out */
>> +	pm_runtime_disable(&pdev->dev);
>>  	return 0;
>>  };
>>  
>> 
>
> I'll rather implement true runtime PM instead,

While this is a minimum implementation, can you explain what you mean by
"true" runtime PM?

Kevin



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