[Intel-gfx] [PATCH v2 09/14] drm/i915: Fix edp vdd locking

Imre Deak imre.deak at intel.com
Tue Sep 2 15:07:07 CEST 2014


On Tue, 2014-08-19 at 20:32 +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Introduce a new mutex (pps_mutex) to protect the power sequencer
> state. For now this state includes want_panel_vdd as well as the
> power sequencer registers.
> 
> We need a single mutex (as opposed to per port) because later on we
> will need to deal with VLV/CHV which have multiple power sequencer
> which can be reassigned to different ports.
> 
> v2: Add the locking to intel_dp_encoder_suspend too (Imre)
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h      |  3 ++
>  drivers/gpu/drm/i915/intel_display.c |  2 +
>  drivers/gpu/drm/i915/intel_dp.c      | 99 ++++++++++++++++++++++++++++++++----
>  3 files changed, 93 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 6fbd316..c5faefb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1501,6 +1501,9 @@ struct drm_i915_private {
>  	/* LVDS info */
>  	bool no_aux_handshake;
>  
> +	/* protects panel power sequencer state */
> +	struct mutex pps_mutex;
> +
>  	struct drm_i915_fence_reg fence_regs[I915_MAX_NUM_FENCES]; /* assume 965 */
>  	int fence_reg_start; /* 4 if userland hasn't ioctl'd us yet */
>  	int num_fence_regs; /* 8 on pre-965, 16 otherwise */
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 0b327eb..ff86729 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12437,6 +12437,8 @@ static void intel_init_display(struct drm_device *dev)
>  	}
>  
>  	intel_panel_init_backlight_funcs(dev);
> +
> +	mutex_init(&dev_priv->pps_mutex);
>  }
>  
>  /*
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 9efa6bf..446df28 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -300,6 +300,8 @@ vlv_power_sequencer_pipe(struct intel_dp *intel_dp)
>  	enum port port = intel_dig_port->port;
>  	enum pipe pipe;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	/* modeset should have pipe */
>  	if (crtc)
>  		return to_intel_crtc(crtc)->pipe;
> @@ -352,6 +354,8 @@ static int edp_notify_handler(struct notifier_block *this, unsigned long code,
>  	if (!IS_VALLEYVIEW(dev) || !is_edp(intel_dp) || code != SYS_RESTART)
>  		return 0;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +

This needs rebasing since 02/14 wasn't applied.

>  	pipe = vlv_power_sequencer_pipe(intel_dp);
>  
>  	pp_ctrl_reg = VLV_PIPE_PP_CONTROL(pipe);
> @@ -364,6 +368,8 @@ static int edp_notify_handler(struct notifier_block *this, unsigned long code,
>  	I915_WRITE(pp_ctrl_reg, PANEL_UNLOCK_REGS | PANEL_POWER_OFF);
>  	msleep(intel_dp->panel_power_cycle_delay);
>  
> +	mutex_unlock(&dev_priv->pps_mutex);
> +
>  	return 0;
>  }
>  
> @@ -372,6 +378,8 @@ static bool edp_have_panel_power(struct intel_dp *intel_dp)
>  	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	return (I915_READ(_pp_stat_reg(intel_dp)) & PP_ON) != 0;
>  }
>  
> @@ -383,6 +391,8 @@ static bool edp_have_panel_vdd(struct intel_dp *intel_dp)
>  	struct intel_encoder *intel_encoder = &intel_dig_port->base;
>  	enum intel_display_power_domain power_domain;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	power_domain = intel_display_port_power_domain(intel_encoder);
>  	return intel_display_power_enabled(dev_priv, power_domain) &&
>  	       (I915_READ(_pp_ctrl_reg(intel_dp)) & EDP_FORCE_VDD) != 0;
> @@ -533,6 +543,8 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
>  	bool has_aux_irq = HAS_AUX_IRQ(dev);
>  	bool vdd;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	/*
>  	 * We will be called with VDD already enabled for dpcd/edid/oui reads.
>  	 * In such cases we want to leave VDD enabled and it's up to upper layers
> @@ -648,6 +660,8 @@ out:
>  	if (vdd)
>  		edp_panel_vdd_off(intel_dp, false);
>  
> +	mutex_unlock(&dev_priv->pps_mutex);
> +
>  	return ret;
>  }
>  
> @@ -1102,6 +1116,8 @@ static void wait_panel_status(struct intel_dp *intel_dp,
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	u32 pp_stat_reg, pp_ctrl_reg;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	pp_stat_reg = _pp_stat_reg(intel_dp);
>  	pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
>  
> @@ -1165,6 +1181,8 @@ static  u32 ironlake_get_pp_control(struct intel_dp *intel_dp)
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	u32 control;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	control = I915_READ(_pp_ctrl_reg(intel_dp));
>  	control &= ~PANEL_UNLOCK_MASK;
>  	control |= PANEL_UNLOCK_REGS;
> @@ -1182,6 +1200,8 @@ static bool edp_panel_vdd_on(struct intel_dp *intel_dp)
>  	u32 pp_stat_reg, pp_ctrl_reg;
>  	bool need_to_disable = !intel_dp->want_panel_vdd;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	if (!is_edp(intel_dp))
>  		return false;
>  
> @@ -1221,12 +1241,16 @@ static bool edp_panel_vdd_on(struct intel_dp *intel_dp)
>  
>  void intel_edp_panel_vdd_on(struct intel_dp *intel_dp)
>  {
> +	struct drm_i915_private *dev_priv =
> +		intel_dp_to_dev(intel_dp)->dev_private;
>  	bool vdd;
>  
>  	if (!is_edp(intel_dp))
>  		return;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
>  	vdd = edp_panel_vdd_on(intel_dp);
> +	mutex_unlock(&dev_priv->pps_mutex);
>  
>  	WARN(!vdd, "eDP VDD already requested on\n");
>  }
> @@ -1242,7 +1266,7 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
>  	u32 pp;
>  	u32 pp_stat_reg, pp_ctrl_reg;
>  
> -	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
> +	lockdep_assert_held(&dev_priv->pps_mutex);
>  
>  	WARN_ON(intel_dp->want_panel_vdd);
>  
> @@ -1275,12 +1299,13 @@ static void edp_panel_vdd_work(struct work_struct *__work)
>  {
>  	struct intel_dp *intel_dp = container_of(to_delayed_work(__work),
>  						 struct intel_dp, panel_vdd_work);
> -	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv =
> +		intel_dp_to_dev(intel_dp)->dev_private;
>  
> -	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> +	mutex_lock(&dev_priv->pps_mutex);
>  	if (!intel_dp->want_panel_vdd)
>  		edp_panel_vdd_off_sync(intel_dp);
> -	drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp)
> @@ -1298,6 +1323,11 @@ static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp)
>  
>  static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
>  {
> +	struct drm_i915_private *dev_priv =
> +		intel_dp_to_dev(intel_dp)->dev_private;
> +
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	if (!is_edp(intel_dp))
>  		return;
>  
> @@ -1313,7 +1343,15 @@ static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
>  
>  static void intel_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
>  {
> +	struct drm_i915_private *dev_priv =
> +		intel_dp_to_dev(intel_dp)->dev_private;
> +
> +	if (!is_edp(intel_dp))
> +		return;
> +
> +	mutex_lock(&dev_priv->pps_mutex);
>  	edp_panel_vdd_off(intel_dp, sync);
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  void intel_edp_panel_on(struct intel_dp *intel_dp)
> @@ -1328,9 +1366,11 @@ void intel_edp_panel_on(struct intel_dp *intel_dp)
>  
>  	DRM_DEBUG_KMS("Turn eDP power on\n");
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	if (edp_have_panel_power(intel_dp)) {
>  		DRM_DEBUG_KMS("eDP power already on\n");
> -		return;
> +		goto out;
>  	}
>  
>  	wait_panel_power_cycle(intel_dp);
> @@ -1359,6 +1399,9 @@ void intel_edp_panel_on(struct intel_dp *intel_dp)
>  		I915_WRITE(pp_ctrl_reg, pp);
>  		POSTING_READ(pp_ctrl_reg);
>  	}
> +
> + out:
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  void intel_edp_panel_off(struct intel_dp *intel_dp)
> @@ -1376,6 +1419,8 @@ void intel_edp_panel_off(struct intel_dp *intel_dp)
>  
>  	DRM_DEBUG_KMS("Turn eDP power off\n");
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	WARN(!intel_dp->want_panel_vdd, "Need VDD to turn off panel\n");
>  
>  	pp = ironlake_get_pp_control(intel_dp);
> @@ -1397,6 +1442,8 @@ void intel_edp_panel_off(struct intel_dp *intel_dp)
>  	/* We got a reference when we enabled the VDD. */
>  	power_domain = intel_display_port_power_domain(intel_encoder);
>  	intel_display_power_put(dev_priv, power_domain);
> +
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  void intel_edp_backlight_on(struct intel_dp *intel_dp)
> @@ -1421,6 +1468,9 @@ void intel_edp_backlight_on(struct intel_dp *intel_dp)
>  	 * allowing it to appear.
>  	 */
>  	wait_backlight_on(intel_dp);
> +
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	pp = ironlake_get_pp_control(intel_dp);
>  	pp |= EDP_BLC_ENABLE;
>  
> @@ -1428,6 +1478,8 @@ void intel_edp_backlight_on(struct intel_dp *intel_dp)
>  
>  	I915_WRITE(pp_ctrl_reg, pp);
>  	POSTING_READ(pp_ctrl_reg);
> +
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  void intel_edp_backlight_off(struct intel_dp *intel_dp)
> @@ -1440,6 +1492,8 @@ void intel_edp_backlight_off(struct intel_dp *intel_dp)
>  	if (!is_edp(intel_dp))
>  		return;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	DRM_DEBUG_KMS("\n");
>  	pp = ironlake_get_pp_control(intel_dp);
>  	pp &= ~EDP_BLC_ENABLE;
> @@ -1448,8 +1502,10 @@ void intel_edp_backlight_off(struct intel_dp *intel_dp)
>  
>  	I915_WRITE(pp_ctrl_reg, pp);
>  	POSTING_READ(pp_ctrl_reg);
> -	intel_dp->last_backlight_off = jiffies;
>  
> +	mutex_unlock(&dev_priv->pps_mutex);
> +
> +	intel_dp->last_backlight_off = jiffies;
>  	edp_wait_backlight_off(intel_dp);
>  
>  	intel_panel_disable_backlight(intel_dp->attached_connector);

These need to be rebased on the latest backlight changes, moving the
locking into _intel_edp_backlight_on/off() and adding it to
intel_edp_backlight_power().

With the above things rebased the patch looks ok to me:
Reviewed-by: Imre Deak <imre.deak at intel.com>

> @@ -2182,9 +2238,11 @@ static void vlv_pre_enable_dp(struct intel_encoder *encoder)
>  
>  	if (is_edp(intel_dp)) {
>  		/* init power sequencer on this pipe and port */
> +		mutex_lock(&dev_priv->pps_mutex);
>  		intel_dp_init_panel_power_sequencer(dev, intel_dp, &power_seq);
>  		intel_dp_init_panel_power_sequencer_registers(dev, intel_dp,
>  							      &power_seq);
> +		mutex_unlock(&dev_priv->pps_mutex);
>  	}
>  
>  	intel_enable_dp(encoder);
> @@ -2284,9 +2342,11 @@ static void chv_pre_enable_dp(struct intel_encoder *encoder)
>  
>  	if (is_edp(intel_dp)) {
>  		/* init power sequencer on this pipe and port */
> +		mutex_lock(&dev_priv->pps_mutex);
>  		intel_dp_init_panel_power_sequencer(dev, intel_dp, &power_seq);
>  		intel_dp_init_panel_power_sequencer_registers(dev, intel_dp,
>  							      &power_seq);
> +		mutex_unlock(&dev_priv->pps_mutex);
>  	}
>  
>  	intel_enable_dp(encoder);
> @@ -4027,15 +4087,16 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
>  	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
>  	struct intel_dp *intel_dp = &intel_dig_port->dp;
>  	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
>  
>  	drm_dp_aux_unregister(&intel_dp->aux);
>  	intel_dp_mst_encoder_cleanup(intel_dig_port);
>  	drm_encoder_cleanup(encoder);
>  	if (is_edp(intel_dp)) {
>  		cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
> -		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> +		mutex_lock(&dev_priv->pps_mutex);
>  		edp_panel_vdd_off_sync(intel_dp);
> -		drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +		mutex_unlock(&dev_priv->pps_mutex);
>  		if (intel_dp->edp_notifier.notifier_call) {
>  			unregister_reboot_notifier(&intel_dp->edp_notifier);
>  			intel_dp->edp_notifier.notifier_call = NULL;
> @@ -4047,11 +4108,15 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
>  static void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
>  {
>  	struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
>  
>  	if (!is_edp(intel_dp))
>  		return;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
>  	edp_panel_vdd_off_sync(intel_dp);
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  static void intel_dp_encoder_reset(struct drm_encoder *encoder)
> @@ -4232,6 +4297,8 @@ intel_dp_init_panel_power_sequencer(struct drm_device *dev,
>  	u32 pp_on, pp_off, pp_div, pp;
>  	int pp_ctrl_reg, pp_on_reg, pp_off_reg, pp_div_reg;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	if (HAS_PCH_SPLIT(dev)) {
>  		pp_ctrl_reg = PCH_PP_CONTROL;
>  		pp_on_reg = PCH_PP_ON_DELAYS;
> @@ -4333,6 +4400,8 @@ intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
>  	int pp_on_reg, pp_off_reg, pp_div_reg;
>  	enum port port = dp_to_dig_port(intel_dp)->port;
>  
> +	lockdep_assert_held(&dev_priv->pps_mutex);
> +
>  	if (HAS_PCH_SPLIT(dev)) {
>  		pp_on_reg = PCH_PP_ON_DELAYS;
>  		pp_off_reg = PCH_PP_OFF_DELAYS;
> @@ -4525,9 +4594,11 @@ void intel_edp_panel_vdd_sanitize(struct intel_encoder *intel_encoder)
>  	if (intel_encoder->type != INTEL_OUTPUT_EDP)
>  		return;
>  
> +	mutex_lock(&dev_priv->pps_mutex);
> +
>  	intel_dp = enc_to_intel_dp(&intel_encoder->base);
>  	if (!edp_have_panel_vdd(intel_dp))
> -		return;
> +		goto out;
>  	/*
>  	 * The VDD bit needs a power domain reference, so if the bit is
>  	 * already enabled when we boot or resume, grab this reference and
> @@ -4539,6 +4610,8 @@ void intel_edp_panel_vdd_sanitize(struct intel_encoder *intel_encoder)
>  	intel_display_power_get(dev_priv, power_domain);
>  
>  	edp_panel_vdd_schedule_off(intel_dp);
> + out:
> +	mutex_unlock(&dev_priv->pps_mutex);
>  }
>  
>  static bool intel_edp_init_connector(struct intel_dp *intel_dp,
> @@ -4580,7 +4653,9 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  	}
>  
>  	/* We now know it's not a ghost, init power sequence regs. */
> +	mutex_lock(&dev_priv->pps_mutex);
>  	intel_dp_init_panel_power_sequencer_registers(dev, intel_dp, power_seq);
> +	mutex_unlock(&dev_priv->pps_mutex);
>  
>  	mutex_lock(&dev->mode_config.mutex);
>  	edid = drm_get_edid(connector, &intel_dp->aux.ddc);
> @@ -4712,8 +4787,10 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
>  	}
>  
>  	if (is_edp(intel_dp)) {
> +		mutex_lock(&dev_priv->pps_mutex);
>  		intel_dp_init_panel_power_timestamps(intel_dp);
>  		intel_dp_init_panel_power_sequencer(dev, intel_dp, &power_seq);
> +		mutex_unlock(&dev_priv->pps_mutex);
>  	}
>  
>  	intel_dp_aux_init(intel_dp, intel_connector);
> @@ -4729,9 +4806,9 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
>  		drm_dp_aux_unregister(&intel_dp->aux);
>  		if (is_edp(intel_dp)) {
>  			cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
> -			drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> +			mutex_lock(&dev_priv->pps_mutex);
>  			edp_panel_vdd_off_sync(intel_dp);
> -			drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +			mutex_unlock(&dev_priv->pps_mutex);
>  		}
>  		drm_connector_unregister(connector);
>  		drm_connector_cleanup(connector);

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