Re: [Intel-gfx] [PATCH 1/7] drm/i915: Move vblank waits out from IPS code

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 09 Feb 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Hoist the IPS related vblank waits one level up. Later on we'll
> want to consolidate all the potential pre-plane update vblank
> waits into one so we can't be hiding any in low level code.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 19 ++++++++++++-------
>  drivers/gpu/drm/i915/display/intel_display.h |  2 +-
>  2 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 7f512f9e9e5c..5cc142a83ad7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -752,8 +752,9 @@ void intel_plane_disable_noatomic(struct intel_crtc *crtc,
>  	crtc_state->data_rate[plane->id] = 0;
>  	crtc_state->min_cdclk[plane->id] = 0;
>  
> -	if (plane->id == PLANE_PRIMARY)
> -		hsw_disable_ips(crtc_state);
> +	if (plane->id == PLANE_PRIMARY &&
> +	    hsw_disable_ips(crtc_state))
> +		intel_crtc_wait_for_next_vblank(crtc);
>  
>  	/*
>  	 * Vblank time updates from the shadow to live plane control register
> @@ -1127,14 +1128,15 @@ void hsw_enable_ips(const struct intel_crtc_state *crtc_state)
>  	}
>  }
>  
> -void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
> +bool hsw_disable_ips(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	struct drm_device *dev = crtc->base.dev;
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> +	bool need_vblank_wait = false;
>  
>  	if (!crtc_state->ips_enabled)
> -		return;
> +		return need_vblank_wait;
>  
>  	if (IS_BROADWELL(dev_priv)) {
>  		drm_WARN_ON(dev,
> @@ -1153,7 +1155,9 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
>  	}
>  
>  	/* We need to wait for a vblank before we can disable the plane. */
> -	intel_crtc_wait_for_next_vblank(crtc);
> +	need_vblank_wait = true;
> +
> +	return need_vblank_wait;
>  }
>  
>  static void intel_crtc_dpms_overlay_disable(struct intel_crtc *crtc)
> @@ -1426,8 +1430,9 @@ static void intel_pre_plane_update(struct intel_atomic_state *state,
>  
>  	intel_psr_pre_plane_update(state, crtc);
>  
> -	if (hsw_pre_update_disable_ips(old_crtc_state, new_crtc_state))
> -		hsw_disable_ips(old_crtc_state);
> +	if (hsw_pre_update_disable_ips(old_crtc_state, new_crtc_state) &&
> +	    hsw_disable_ips(old_crtc_state))
> +		intel_crtc_wait_for_next_vblank(crtc);
>  
>  	if (intel_fbc_pre_update(state, crtc))
>  		intel_crtc_wait_for_next_vblank(crtc);
> diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> index 457738aeee3e..8f9bec36898e 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.h
> +++ b/drivers/gpu/drm/i915/display/intel_display.h
> @@ -634,7 +634,7 @@ void i9xx_crtc_clock_get(struct intel_crtc *crtc,
>  int intel_dotclock_calculate(int link_freq, const struct intel_link_m_n *m_n);
>  bool hsw_crtc_state_ips_capable(const struct intel_crtc_state *crtc_state);
>  void hsw_enable_ips(const struct intel_crtc_state *crtc_state);
> -void hsw_disable_ips(const struct intel_crtc_state *crtc_state);
> +bool hsw_disable_ips(const struct intel_crtc_state *crtc_state);
>  enum intel_display_power_domain intel_port_to_power_domain(enum port port);
>  enum intel_display_power_domain
>  intel_aux_power_domain(struct intel_digital_port *dig_port);

-- 
Jani Nikula, Intel Open Source Graphics Center