[Intel-gfx] [PATCH v2 1/1] drm/i915: Hold RPM reference while setting freq limits through sysfs

[Ville Syrjälä]

On Mon, Feb 08, 2016 at 10:47:11PM +0530, Sagar Arun Kamble wrote:
> This changes ensures device is active when frequency limits are changed.
> This is needed as we are writing to register RPNSWREQ in intel_set_rps.
> If not done, might lead to undesired errors like:
> [ 1965.189137] [drm:fw_domains_get] *ERROR* blitter: timed out waiting for forcewake ack to clear.
> 
> v2: Added elaborate commit message. (Jani)
>     Fixing RPM reference drop in early exit paths. (Ville)
> 
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_sysfs.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
> index c6188dd..2d576b7 100644
> --- a/drivers/gpu/drm/i915/i915_sysfs.c
> +++ b/drivers/gpu/drm/i915/i915_sysfs.c
> @@ -370,6 +370,8 @@ static ssize_t gt_max_freq_mhz_store(struct device *kdev,
>  
>  	flush_delayed_work(&dev_priv->rps.delayed_resume_work);
>  
> +	intel_runtime_pm_get(dev_priv);
> +
>  	mutex_lock(&dev_priv->rps.hw_lock);
>  
>  	val = intel_freq_opcode(dev_priv, val);
> @@ -378,6 +380,7 @@ static ssize_t gt_max_freq_mhz_store(struct device *kdev,
>  	    val > dev_priv->rps.max_freq ||
>  	    val < dev_priv->rps.min_freq_softlimit) {
>  		mutex_unlock(&dev_priv->rps.hw_lock);
> +		intel_runtime_pm_put(dev_priv);
>  		return -EINVAL;
>  	}
>  
> @@ -398,6 +401,8 @@ static ssize_t gt_max_freq_mhz_store(struct device *kdev,
>  
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  
> +	intel_runtime_pm_put(dev_priv);
> +
>  	return count;
>  }
>  
> @@ -433,6 +438,8 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
>  
>  	flush_delayed_work(&dev_priv->rps.delayed_resume_work);
>  
> +	intel_runtime_pm_get(dev_priv);
> +
>  	mutex_lock(&dev_priv->rps.hw_lock);
>  
>  	val = intel_freq_opcode(dev_priv, val);
> @@ -441,6 +448,7 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
>  	    val > dev_priv->rps.max_freq ||
>  	    val > dev_priv->rps.max_freq_softlimit) {
>  		mutex_unlock(&dev_priv->rps.hw_lock);
> +		intel_runtime_pm_put(dev_priv);
>  		return -EINVAL;
>  	}
>  
> @@ -457,6 +465,8 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
>  
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  
> +	intel_runtime_pm_put(dev_priv);
> +
>  	return count;
>  
>  }
> -- 
> 1.9.1
> 
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-- 
Ville Syrjälä
Intel OTC