Re: [Intel-gfx] [PATCH 09/13] drm/i915: Add crtc .crtc_get_shared_dpll()

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

On Fri, 25 Mar 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Start splitting the .compute_crtc_clock() into two parts; one
> part does the computation, the second part does the shared dpll
> assignment. I want to move the actual computation part much earlier
> into the compute_config() phase.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c |  4 ++
>  drivers/gpu/drm/i915/display/intel_dpll.c    | 54 +++++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_dpll.h    |  2 +
>  3 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 7c68bc07c925..1b7bc764498c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -5003,6 +5003,10 @@ static int intel_crtc_atomic_check(struct intel_atomic_state *state,
>  		ret = intel_dpll_crtc_compute_clock(state, crtc);
>  		if (ret)
>  			return ret;
> +
> +		ret = intel_dpll_crtc_get_shared_dpll(state, crtc);
> +		if (ret)
> +			return ret;
>  	}
>  
>  	/*
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll.c b/drivers/gpu/drm/i915/display/intel_dpll.c
> index bc59efe18e89..2ee7255f3c36 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpll.c
> @@ -20,6 +20,8 @@
>  struct intel_dpll_funcs {
>  	int (*crtc_compute_clock)(struct intel_atomic_state *state,
>  				  struct intel_crtc *crtc);
> +	int (*crtc_get_shared_dpll)(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc);
>  };
>  
>  struct intel_limit {
> @@ -930,6 +932,12 @@ static void i8xx_compute_dpll(struct intel_crtc_state *crtc_state,
>  
>  static int hsw_crtc_compute_clock(struct intel_atomic_state *state,
>  				  struct intel_crtc *crtc)
> +{
> +	return 0;
> +}
> +
> +static int hsw_crtc_get_shared_dpll(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
>  	struct intel_crtc_state *crtc_state =
> @@ -964,6 +972,12 @@ static int dg2_crtc_compute_clock(struct intel_atomic_state *state,
>  	return intel_mpllb_calc_state(crtc_state, encoder);
>  }
>  
> +static int dg2_crtc_get_shared_dpll(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc)
> +{
> +	return 0;
> +}
> +

This seems superfluous at this time because
intel_dpll_crtc_get_shared_dpll() checks for NULL
.crtc_get_shared_dpll() and does exactly that.

Not a biggie.

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


>  static bool ilk_needs_fb_cb_tune(const struct dpll *dpll, int factor)
>  {
>  	return dpll->m < factor * dpll->n;
> @@ -1087,7 +1101,6 @@ static int ilk_crtc_compute_clock(struct intel_atomic_state *state,
>  		intel_atomic_get_new_crtc_state(state, crtc);
>  	const struct intel_limit *limit;
>  	int refclk = 120000;
> -	int ret;
>  
>  	/* CPU eDP is the only output that doesn't need a PCH PLL of its own. */
>  	if (!crtc_state->has_pch_encoder)
> @@ -1127,6 +1140,21 @@ static int ilk_crtc_compute_clock(struct intel_atomic_state *state,
>  	ilk_compute_dpll(crtc_state, &crtc_state->dpll,
>  			 &crtc_state->dpll);
>  
> +	return 0;
> +}
> +
> +static int ilk_crtc_get_shared_dpll(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> +	struct intel_crtc_state *crtc_state =
> +		intel_atomic_get_new_crtc_state(state, crtc);
> +	int ret;
> +
> +	/* CPU eDP is the only output that doesn't need a PCH PLL of its own. */
> +	if (!crtc_state->has_pch_encoder)
> +		return 0;
> +
>  	ret = intel_reserve_shared_dplls(state, crtc, NULL);
>  	if (ret) {
>  		drm_dbg_kms(&dev_priv->drm,
> @@ -1372,14 +1400,17 @@ static int i8xx_crtc_compute_clock(struct intel_atomic_state *state,
>  
>  static const struct intel_dpll_funcs dg2_dpll_funcs = {
>  	.crtc_compute_clock = dg2_crtc_compute_clock,
> +	.crtc_get_shared_dpll = dg2_crtc_get_shared_dpll,
>  };
>  
>  static const struct intel_dpll_funcs hsw_dpll_funcs = {
>  	.crtc_compute_clock = hsw_crtc_compute_clock,
> +	.crtc_get_shared_dpll = hsw_crtc_get_shared_dpll,
>  };
>  
>  static const struct intel_dpll_funcs ilk_dpll_funcs = {
>  	.crtc_compute_clock = ilk_crtc_compute_clock,
> +	.crtc_get_shared_dpll = ilk_crtc_get_shared_dpll,
>  };
>  
>  static const struct intel_dpll_funcs chv_dpll_funcs = {
> @@ -1427,6 +1458,27 @@ int intel_dpll_crtc_compute_clock(struct intel_atomic_state *state,
>  	return i915->dpll_funcs->crtc_compute_clock(state, crtc);
>  }
>  
> +int intel_dpll_crtc_get_shared_dpll(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc)
> +{
> +	struct drm_i915_private *i915 = to_i915(state->base.dev);
> +	struct intel_crtc_state *crtc_state =
> +		intel_atomic_get_new_crtc_state(state, crtc);
> +
> +	drm_WARN_ON(&i915->drm, !intel_crtc_needs_modeset(crtc_state));
> +
> +	if (drm_WARN_ON(&i915->drm, crtc_state->shared_dpll))
> +		return 0;
> +
> +	if (!crtc_state->hw.enable)
> +		return 0;
> +
> +	if (!i915->dpll_funcs->crtc_get_shared_dpll)
> +		return 0;
> +
> +	return i915->dpll_funcs->crtc_get_shared_dpll(state, crtc);
> +}
> +
>  void
>  intel_dpll_init_clock_hook(struct drm_i915_private *dev_priv)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll.h b/drivers/gpu/drm/i915/display/intel_dpll.h
> index e9731b2dd01c..bbc30542f29f 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll.h
> +++ b/drivers/gpu/drm/i915/display/intel_dpll.h
> @@ -18,6 +18,8 @@ enum pipe;
>  void intel_dpll_init_clock_hook(struct drm_i915_private *dev_priv);
>  int intel_dpll_crtc_compute_clock(struct intel_atomic_state *state,
>  				  struct intel_crtc *crtc);
> +int intel_dpll_crtc_get_shared_dpll(struct intel_atomic_state *state,
> +				    struct intel_crtc *crtc);
>  int vlv_calc_dpll_params(int refclk, struct dpll *clock);
>  int pnv_calc_dpll_params(int refclk, struct dpll *clock);
>  int i9xx_calc_dpll_params(int refclk, struct dpll *clock);

-- 
Jani Nikula, Intel Open Source Graphics Center