[Intel-gfx] [PATCH 2/5] drm/i915/bxt: WaGsvDisableTurbo

[Yu Dai]

Looks fine to me.
Reviewed by: Alex Dai <yu.dai at intel.com>.

On 08/23/2015 05:22 AM, Sagar Arun Kamble wrote:
> Disable Turbo on steppings prior to B0 on BXT due to hangs seen during GT CPD exit.
>
> Change-Id: I50c5c03f59f5ba092db19e17234951d89db42c6c
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_pm.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index fff0c22..75f1c8c 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4450,6 +4450,10 @@ static void gen6_set_rps(struct drm_device *dev, u8 val)
>   {
>   	struct drm_i915_private *dev_priv = dev->dev_private;
>   
> +	/* WaGsvDisableTurbo: Workaround to disable turbo on BXT A* */
> +	if (IS_BROXTON(dev) && (INTEL_REVID(dev) < BXT_REVID_B0))
> +		return;
> +
>   	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
>   	WARN_ON(val > dev_priv->rps.max_freq);
>   	WARN_ON(val < dev_priv->rps.min_freq);
> @@ -4770,6 +4774,12 @@ static void gen9_enable_rps(struct drm_device *dev)
>   
>   	gen6_init_rps_frequencies(dev);
>   
> +	/* WaGsvDisableTurbo: Workaround to disable turbo on BXT A* */
> +	if (IS_BROXTON(dev) && (INTEL_REVID(dev) < BXT_REVID_B0)) {
> +		intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
> +		return;
> +	}
> +
>   	/* Program defaults and thresholds for RPS*/
>   	I915_WRITE(GEN6_RC_VIDEO_FREQ,
>   		GEN9_FREQUENCY(dev_priv->rps.rp1_freq));