diff mbox

[10/15] drm/i915: Force common lane on for the PPS kick on CHV

Message ID 1436388361-11130-11-git-send-email-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ville Syrjälä July 8, 2015, 8:45 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

With DPIO powergating active the DPLL can't be accessed unless
something else is keeping the common lane in the channel on.
That means the PPS kick procedure could fail to enable the PLL.

Power up some data lanes to force the common lane to power up
so that the PLL can be enabled temporarily.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

Comments

deepak.s@linux.intel.com Aug. 19, 2015, 2:21 a.m. UTC | #1 
On 07/09/2015 02:15 AM, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> With DPIO powergating active the DPLL can't be accessed unless
> something else is keeping the common lane in the channel on.
> That means the PPS kick procedure could fail to enable the PLL.
>
> Power up some data lanes to force the common lane to power up
> so that the PLL can be enabled temporarily.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>   drivers/gpu/drm/i915/intel_dp.c | 16 +++++++++++++---
>   1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 8d088f3..817df87 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -341,7 +341,9 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
>   	struct drm_device *dev = intel_dig_port->base.base.dev;
>   	struct drm_i915_private *dev_priv = dev->dev_private;
>   	enum pipe pipe = intel_dp->pps_pipe;
> -	bool pll_enabled;
> +	bool pll_enabled, release_cl_override;
> +	enum dpio_phy phy = DPIO_PHY(pipe);
> +	enum dpio_channel ch = vlv_pipe_to_channel(pipe);
>   	uint32_t DP;
>   
>   	if (WARN(I915_READ(intel_dp->output_reg) & DP_PORT_EN,
> @@ -371,9 +373,13 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
>   	 * The DPLL for the pipe must be enabled for this to work.
>   	 * So enable temporarily it if it's not already enabled.
>   	 */
> -	if (!pll_enabled)
> +	if (!pll_enabled) {
> +		release_cl_override = IS_CHERRYVIEW(dev) &&
> +			!chv_phy_powergate_ch(dev_priv, phy, ch, true);
> +
>   		vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
>   				 &chv_dpll[0].dpll : &vlv_dpll[0].dpll);
> +	}
>   
>   	/*
>   	 * Similar magic as in intel_dp_enable_port().
> @@ -390,8 +396,12 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
>   	I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
>   	POSTING_READ(intel_dp->output_reg);
>   
> -	if (!pll_enabled)
> +	if (!pll_enabled) {
>   		vlv_force_pll_off(dev, pipe);
> +
> +		if (release_cl_override)
> +			chv_phy_powergate_ch(dev_priv, phy, ch, false);
> +	}
>   }
>   
>   static enum pipe
Change looks fine
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Ville Syrjälä Aug. 19, 2015, 11:32 a.m. UTC | #2 
On Wed, Aug 19, 2015 at 07:51:57AM +0530, Deepak wrote:
> 
> 
> On 07/09/2015 02:15 AM, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > With DPIO powergating active the DPLL can't be accessed unless
> > something else is keeping the common lane in the channel on.
> > That means the PPS kick procedure could fail to enable the PLL.
> >
> > Power up some data lanes to force the common lane to power up
> > so that the PLL can be enabled temporarily.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >   drivers/gpu/drm/i915/intel_dp.c | 16 +++++++++++++---
> >   1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 8d088f3..817df87 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -341,7 +341,9 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
> >   	struct drm_device *dev = intel_dig_port->base.base.dev;
> >   	struct drm_i915_private *dev_priv = dev->dev_private;
> >   	enum pipe pipe = intel_dp->pps_pipe;
> > -	bool pll_enabled;
> > +	bool pll_enabled, release_cl_override;
> > +	enum dpio_phy phy = DPIO_PHY(pipe);
> > +	enum dpio_channel ch = vlv_pipe_to_channel(pipe);
> >   	uint32_t DP;
> >   
> >   	if (WARN(I915_READ(intel_dp->output_reg) & DP_PORT_EN,
> > @@ -371,9 +373,13 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
> >   	 * The DPLL for the pipe must be enabled for this to work.
> >   	 * So enable temporarily it if it's not already enabled.
> >   	 */
> > -	if (!pll_enabled)
> > +	if (!pll_enabled) {
> > +		release_cl_override = IS_CHERRYVIEW(dev) &&
> > +			!chv_phy_powergate_ch(dev_priv, phy, ch, true);
> > +
> >   		vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
> >   				 &chv_dpll[0].dpll : &vlv_dpll[0].dpll);
> > +	}
> >   
> >   	/*
> >   	 * Similar magic as in intel_dp_enable_port().
> > @@ -390,8 +396,12 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
> >   	I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
> >   	POSTING_READ(intel_dp->output_reg);
> >   
> > -	if (!pll_enabled)
> > +	if (!pll_enabled) {
> >   		vlv_force_pll_off(dev, pipe);
> > +
> > +		if (release_cl_override)
> > +			chv_phy_powergate_ch(dev_priv, phy, ch, false);
> > +	}
> >   }
> >   
> >   static enum pipe
> Change looks fine
> Reviewed-by: Deepak S <deepak.s@linux.intel.com>

Note to Daniel: Please pick up v2 of this patch. The only change
was release_cl_override=false initialization to avoid a gcc warning.
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8d088f3..817df87 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -341,7 +341,9 @@  vlv_power_sequencer_kick(struct intel_dp *intel_dp)
 	struct drm_device *dev = intel_dig_port->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	enum pipe pipe = intel_dp->pps_pipe;
-	bool pll_enabled;
+	bool pll_enabled, release_cl_override;
+	enum dpio_phy phy = DPIO_PHY(pipe);
+	enum dpio_channel ch = vlv_pipe_to_channel(pipe);
 	uint32_t DP;
 
 	if (WARN(I915_READ(intel_dp->output_reg) & DP_PORT_EN,
@@ -371,9 +373,13 @@  vlv_power_sequencer_kick(struct intel_dp *intel_dp)
 	 * The DPLL for the pipe must be enabled for this to work.
 	 * So enable temporarily it if it's not already enabled.
 	 */
-	if (!pll_enabled)
+	if (!pll_enabled) {
+		release_cl_override = IS_CHERRYVIEW(dev) &&
+			!chv_phy_powergate_ch(dev_priv, phy, ch, true);
+
 		vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
 				 &chv_dpll[0].dpll : &vlv_dpll[0].dpll);
+	}
 
 	/*
 	 * Similar magic as in intel_dp_enable_port().
@@ -390,8 +396,12 @@  vlv_power_sequencer_kick(struct intel_dp *intel_dp)
 	I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
 	POSTING_READ(intel_dp->output_reg);
 
-	if (!pll_enabled)
+	if (!pll_enabled) {
 		vlv_force_pll_off(dev, pipe);
+
+		if (release_cl_override)
+			chv_phy_powergate_ch(dev_priv, phy, ch, false);
+	}
 }
 
 static enum pipe