Re: [PATCH 08/15] drm/i915/display: Refactor enable_joiner_pipes

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

On Thu, Sep 26, 2024 at 12:56:31PM +0530, Ankit Nautiyal wrote:
> Pass the current pipe into enabled_joiner_pipes(), and let it figure out
> the proper bitmasks for us. Since the enabled_joiner_pipes now gets the
> primary and secondary pipe wrt a given pipe, the helpers
> to get primary pipe and secondary pipes are no longer required.
> 
> v2:
> -Simplify helper get_joiner_primary_pipes. (Ville)
> -Nuke get_joiner_secondary_pipes. (Ville)
> -Add more drm_WARNs final primary/secondary pipes. (Ville)
> v3:
> -Drop ultrajoiner stuff and add it in subsequent patches. (Ville)
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 89 ++++++++++----------
>  1 file changed, 44 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 2d6260c3bca5..ea259b142786 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -3663,7 +3663,15 @@ static u8 expected_bigjoiner_secondary_pipes(u8 bigjoiner_primary_pipes)
>  	return expected_secondary_pipes(bigjoiner_primary_pipes, 2);
>  }
>  
> +static u8 get_joiner_primary_pipe(enum pipe pipe, u8 primary_pipes)
> +{
> +	primary_pipes &= GENMASK(pipe, 0);
> +
> +	return primary_pipes ? BIT(fls(primary_pipes) - 1) : 0;
> +}
> +
>  static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
> +				 enum pipe pipe,
>  				 u8 *primary_pipes, u8 *secondary_pipes)
>  {
>  	struct intel_display *display = to_intel_display(&dev_priv->drm);
> @@ -3703,45 +3711,38 @@ static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
>  		 expected_uncompressed_joiner_secondary_pipes(primary_uncompressed_joiner_pipes),
>  		 secondary_uncompressed_joiner_pipes);
>  
> -	*primary_pipes = primary_uncompressed_joiner_pipes | primary_bigjoiner_pipes;
> -
> -	*secondary_pipes = secondary_uncompressed_joiner_pipes | secondary_bigjoiner_pipes;
> -
> -	/* Joiner pipes should always be consecutive primary and secondary */
> -	drm_WARN(display->drm, *secondary_pipes != *primary_pipes << 1,
> -		 "Joiner misconfigured (primary pipes %#x, secondary pipes %#x)\n",
> -		 *primary_pipes, *secondary_pipes);
> -}
> -
> -static enum pipe get_joiner_primary_pipe(enum pipe pipe, u8 primary_pipes, u8 secondary_pipes)
> -{
> -	if ((secondary_pipes & BIT(pipe)) == 0)
> -		return pipe;
> -
> -	/* ignore everything above our pipe */
> -	primary_pipes &= ~GENMASK(7, pipe);
> -
> -	/* highest remaining bit should be our primary pipe */
> -	return fls(primary_pipes) - 1;
> -}
> -
> -static u8 get_joiner_secondary_pipes(enum pipe pipe, u8 primary_pipes, u8 secondary_pipes)
> -{
> -	enum pipe primary_pipe, next_primary_pipe;
> -
> -	primary_pipe = get_joiner_primary_pipe(pipe, primary_pipes, secondary_pipes);
> -
> -	if ((primary_pipes & BIT(primary_pipe)) == 0)
> -		return 0;
> -
> -	/* ignore our primary pipe and everything below it */
> -	primary_pipes &= ~GENMASK(primary_pipe, 0);
> -	/* make sure a high bit is set for the ffs() */
> -	primary_pipes |= BIT(7);
> -	/* lowest remaining bit should be the next primary pipe */
> -	next_primary_pipe = ffs(primary_pipes) - 1;
> -
> -	return secondary_pipes & GENMASK(next_primary_pipe - 1, primary_pipe);
> +	*primary_pipes = 0;
> +	*secondary_pipes = 0;
> +
> +	if (uncompressed_joiner_pipes & BIT(pipe)) {
> +		*primary_pipes = get_joiner_primary_pipe(pipe, primary_uncompressed_joiner_pipes);
> +		*secondary_pipes = secondary_uncompressed_joiner_pipes &
> +				   expected_uncompressed_joiner_secondary_pipes(*primary_pipes);
> +
> +		drm_WARN(display->drm,
> +			 expected_uncompressed_joiner_secondary_pipes(*primary_pipes) !=
> +			 *secondary_pipes,
> +			 "Wrong uncompressed joiner secondary pipes for primary_pipes %#x (expected %#x, current %#x)\n",
> +			 *primary_pipes,
> +			 expected_uncompressed_joiner_secondary_pipes(*primary_pipes),
> +			 *secondary_pipes);
> +		return;
> +	}
> +
> +	if (bigjoiner_pipes & BIT(pipe)) {
> +		*primary_pipes = get_joiner_primary_pipe(pipe, primary_bigjoiner_pipes);
> +		*secondary_pipes = secondary_bigjoiner_pipes &
> +				   expected_bigjoiner_secondary_pipes(*primary_pipes);
> +
> +		drm_WARN(display->drm,
> +			 expected_bigjoiner_secondary_pipes(*primary_pipes) !=
> +			 *secondary_pipes,
> +			 "Wrong bigjoiner secondary pipes for primary_pipes %#x (expected %#x, current %#x)\n",
> +			 *primary_pipes,
> +			 expected_bigjoiner_secondary_pipes(*primary_pipes),
> +			 *secondary_pipes);
> +		return;
> +	}
>  }
>  
>  static u8 hsw_panel_transcoders(struct drm_i915_private *i915)
> @@ -3813,10 +3814,10 @@ static u8 hsw_enabled_transcoders(struct intel_crtc *crtc)
>  		enabled_transcoders |= BIT(cpu_transcoder);
>  
>  	/* joiner secondary -> consider the primary pipe's transcoder as well */
> -	enabled_joiner_pipes(dev_priv, &primary_pipes, &secondary_pipes);
> +	enabled_joiner_pipes(dev_priv, crtc->pipe, &primary_pipes, &secondary_pipes);
>  	if (secondary_pipes & BIT(crtc->pipe)) {
>  		cpu_transcoder = (enum transcoder)
> -			get_joiner_primary_pipe(crtc->pipe, primary_pipes, secondary_pipes);
> +			ffs(get_joiner_primary_pipe(crtc->pipe, primary_pipes)) - 1;

The get_joiner_primary_pipe() shouldn't be needed here since
enabled_joiner_pipes() guarantees that only one bit is set.

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

>  		if (transcoder_ddi_func_is_enabled(dev_priv, cpu_transcoder))
>  			enabled_transcoders |= BIT(cpu_transcoder);
>  	}
> @@ -3950,14 +3951,12 @@ static void intel_joiner_get_config(struct intel_crtc_state *crtc_state)
>  	u8 primary_pipes, secondary_pipes;
>  	enum pipe pipe = crtc->pipe;
>  
> -	enabled_joiner_pipes(i915, &primary_pipes, &secondary_pipes);
> +	enabled_joiner_pipes(i915, pipe, &primary_pipes, &secondary_pipes);
>  
>  	if (((primary_pipes | secondary_pipes) & BIT(pipe)) == 0)
>  		return;
>  
> -	crtc_state->joiner_pipes =
> -		BIT(get_joiner_primary_pipe(pipe, primary_pipes, secondary_pipes)) |
> -		get_joiner_secondary_pipes(pipe, primary_pipes, secondary_pipes);
> +	crtc_state->joiner_pipes = primary_pipes | secondary_pipes;
>  }
>  
>  static bool hsw_get_pipe_config(struct intel_crtc *crtc,
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel