[Intel-gfx] [PATCH 17/31] drm/i915: Add sys PSR toggle interface.

[Chris Wilson]

On Thu, Nov 05, 2015 at 10:50:09AM -0800, Rodrigo Vivi wrote:
> This interface allows an immediate enabling of PSR feature.
> What allow us to see immediately the PSR savings and will
> allow us to expose this through powertop interface.

Pardon? It's a connector property.

> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_sysfs.c | 82 +++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h  |  4 +-
>  drivers/gpu/drm/i915/intel_psr.c  | 19 +++++++--
>  3 files changed, 99 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
> index 2d092c1..0f371c6 100644
> --- a/drivers/gpu/drm/i915/i915_sysfs.c
> +++ b/drivers/gpu/drm/i915/i915_sysfs.c
> @@ -111,6 +111,81 @@ static struct attribute_group ips_attr_group = {
>  	.attrs =  ips_attrs
>  };
>  
> +static ssize_t
> +psr_show(struct device *kdev, struct device_attribute *attr, char *buf)
> +{
> +	struct drm_minor *dminor = dev_to_drm_minor(kdev);
> +	struct drm_device *dev = dminor->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	ssize_t ret;
> +
> +	mutex_lock(&dev_priv->psr.lock);
> +	ret = snprintf(buf, PAGE_SIZE, "%s\n", dev_priv->psr.enabled ?
> +		       "enabled" : "disabled");
> +	mutex_unlock(&dev_priv->psr.lock);

Superfluous locking.

> +
> +	return ret;
> +}
> +
> +
> +static ssize_t
> +psr_toggle(struct device *kdev, struct device_attribute *attr,
> +	   const char *buf, size_t count)
> +{
> +	struct drm_minor *dminor = dev_to_drm_minor(kdev);
> +	struct drm_device *dev = dminor->dev;
> +	struct intel_connector *connector;
> +	struct intel_encoder *encoder;
> +	struct intel_crtc *crtc = NULL;
> +	u32 val;
> +	ssize_t ret;
> +
> +	ret = kstrtou32(buf, 0, &val);
> +	if (ret)
> +		return ret;
> +
> +	for_each_intel_connector(dev, connector) {
> +		if (!connector->base.encoder)
> +			continue;
> +		encoder = to_intel_encoder(connector->base.encoder);
> +		crtc = to_intel_crtc(encoder->base.crtc);
> +	}

"Let's pick a connector at random".
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre