Re: [PATCH v3 21/25] drm/i915: vlv: factor out vlv_force_gfx_clock and check for pending force-off

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Apr 18, 2014 at 04:35:02PM +0300, Imre Deak wrote:
> This will be needed by the VLV runtime PM helpers too, so factor it out.
> 
> Also add a safety check for the case where the previous force-off is
> still pending, since I'm not sure if Punit can handle a new setting
> while the previous one hasn't settled yet.
> 
> v2:
> - unchanged
> v3:
> - add a note to the commit message about the safety check (Ville)
> 
> Signed-off-by: Imre Deak <imre.deak@intel.com>

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

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 37 +++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_drv.h |  1 +
>  drivers/gpu/drm/i915/intel_pm.c | 16 ++--------------
>  3 files changed, 40 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 1f88917..795caea 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -905,6 +905,43 @@ static void hsw_runtime_resume(struct drm_i915_private *dev_priv)
>  	hsw_disable_pc8(dev_priv);
>  }
>  
> +int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
> +{
> +	u32 val;
> +	int err;
> +
> +	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
> +	WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
> +
> +#define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
> +	/* Wait for a previous force-off to settle */
> +	if (force_on) {
> +		err = wait_for(!COND, 5);
> +		if (err) {
> +			DRM_ERROR("timeout waiting for GFX clock force-off (%08x)\n",
> +				  I915_READ(VLV_GTLC_SURVIVABILITY_REG));
> +			return err;
> +		}
> +	}
> +
> +	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
> +	val &= ~VLV_GFX_CLK_FORCE_ON_BIT;
> +	if (force_on)
> +		val |= VLV_GFX_CLK_FORCE_ON_BIT;
> +	I915_WRITE(VLV_GTLC_SURVIVABILITY_REG, val);
> +
> +	if (!force_on)
> +		return 0;
> +
> +	err = wait_for(COND, 5);
> +	if (err)
> +		DRM_ERROR("timeout waiting for GFX clock force-on (%08x)\n",
> +			  I915_READ(VLV_GTLC_SURVIVABILITY_REG));
> +
> +	return err;
> +#undef COND
> +}
> +
>  static int intel_runtime_suspend(struct device *device)
>  {
>  	struct pci_dev *pdev = to_pci_dev(device);
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 5254f4b..3cac434 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1968,6 +1968,7 @@ extern unsigned long i915_chipset_val(struct drm_i915_private *dev_priv);
>  extern unsigned long i915_mch_val(struct drm_i915_private *dev_priv);
>  extern unsigned long i915_gfx_val(struct drm_i915_private *dev_priv);
>  extern void i915_update_gfx_val(struct drm_i915_private *dev_priv);
> +int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool on);
>  
>  extern void intel_console_resume(struct work_struct *work);
>  
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index c45e5c1..d64ac32 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3129,16 +3129,7 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
>  	/* Mask turbo interrupt so that they will not come in between */
>  	I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
>  
> -	/* Bring up the Gfx clock */
> -	I915_WRITE(VLV_GTLC_SURVIVABILITY_REG,
> -		I915_READ(VLV_GTLC_SURVIVABILITY_REG) |
> -				VLV_GFX_CLK_FORCE_ON_BIT);
> -
> -	if (wait_for(((VLV_GFX_CLK_STATUS_BIT &
> -		I915_READ(VLV_GTLC_SURVIVABILITY_REG)) != 0), 5)) {
> -			DRM_ERROR("GFX_CLK_ON request timed out\n");
> -		return;
> -	}
> +	vlv_force_gfx_clock(dev_priv, true);
>  
>  	dev_priv->rps.cur_freq = dev_priv->rps.min_freq_softlimit;
>  
> @@ -3149,10 +3140,7 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
>  				& GENFREQSTATUS) == 0, 5))
>  		DRM_ERROR("timed out waiting for Punit\n");
>  
> -	/* Release the Gfx clock */
> -	I915_WRITE(VLV_GTLC_SURVIVABILITY_REG,
> -		I915_READ(VLV_GTLC_SURVIVABILITY_REG) &
> -				~VLV_GFX_CLK_FORCE_ON_BIT);
> +	vlv_force_gfx_clock(dev_priv, false);
>  
>  	I915_WRITE(GEN6_PMINTRMSK,
>  		   gen6_rps_pm_mask(dev_priv, dev_priv->rps.cur_freq));
> -- 
> 1.8.4
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC