Re: [PATCH 2/2] drm/i915: hw state readout support for pixel_multiplier

[Imre Deak <imre.deak@intel.com>]

On Sat, 2013-06-01 at 17:17 +0200, Daniel Vetter wrote:
> Incomplete since ilk+ support needs proper pch dpll tracking first.
> SDVO get_config parts based on a patch from Jesse Barnes, but fixed up
> to actually work.
> 
> Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 25 +++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_sdvo.c    | 30 +++++++++++++++++++++++++++++-
>  2 files changed, 54 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 9f772eb..f126e18 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4965,6 +4965,23 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
>  
>  	i9xx_get_pfit_config(crtc, pipe_config);
>  
> +	if (INTEL_INFO(dev)->gen >= 4) {
> +		tmp = I915_READ(DPLL_MD(crtc->pipe));
> +		pipe_config->pixel_multiplier =
> +			((tmp & DPLL_MD_UDI_MULTIPLIER_MASK)
> +			 >> DPLL_MD_UDI_MULTIPLIER_SHIFT) + 1;
> +	} else if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev)) {
> +		tmp = I915_READ(DPLL(crtc->pipe));
> +		pipe_config->pixel_multiplier =
> +			((tmp & SDVO_MULTIPLIER_MASK)
> +			 >> SDVO_MULTIPLIER_SHIFT_HIRES) + 1;
> +	} else {
> +		/* Note that on i915G/GM the pixel multiplier is in the sdvo
> +		 * port and will be fixed up in the encoder->get_config
> +		 * function. */
> +		pipe_config->pixel_multiplier = 1;
> +	}
> +
>  	return true;
>  }
>  
> @@ -5828,6 +5845,12 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
>  					  FDI_DP_PORT_WIDTH_SHIFT) + 1;
>  
>  		ironlake_get_fdi_m_n_config(crtc, pipe_config);
> +
> +		/* XXX: Can't properly read out the pch dpll pixel multiplier
> +		 * since we don't have state tracking for pch clocks yet. */
> +		pipe_config->pixel_multiplier = 1;
> +	} else {
> +		pipe_config->pixel_multiplier = 1;
>  	}
>  
>  	intel_get_pipe_timings(crtc, pipe_config);
> @@ -5980,6 +6003,8 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
>  	pipe_config->ips_enabled = hsw_crtc_supports_ips(crtc) &&
>  				   (I915_READ(IPS_CTL) & IPS_ENABLE);
>  
> +	pipe_config->pixel_multiplier = 1;
> +
>  	return true;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
> index f4588a2..5c816dd 100644
> --- a/drivers/gpu/drm/i915/intel_sdvo.c
> +++ b/drivers/gpu/drm/i915/intel_sdvo.c
> @@ -1313,9 +1313,13 @@ static bool intel_sdvo_get_hw_state(struct intel_encoder *encoder,
>  static void intel_sdvo_get_config(struct intel_encoder *encoder,
>  				  struct intel_crtc_config *pipe_config)
>  {
> +	struct drm_device *dev = encoder->base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct intel_sdvo *intel_sdvo = to_intel_sdvo(&encoder->base);
>  	struct intel_sdvo_dtd dtd;
> -	u32 flags = 0;
> +	int encoder_pixel_multiplier = 0;
> +	u32 flags = 0, sdvox;
> +	u8 val;
>  	bool ret;
>  
>  	ret = intel_sdvo_get_input_timing(intel_sdvo, &dtd);
> @@ -1335,6 +1339,30 @@ static void intel_sdvo_get_config(struct intel_encoder *encoder,
>  		flags |= DRM_MODE_FLAG_NVSYNC;
>  
>  	pipe_config->adjusted_mode.flags |= flags;
> +
> +	if (IS_I915G(dev) || IS_I915GM(dev)) {
> +		sdvox = I915_READ(intel_sdvo->sdvo_reg);
> +		pipe_config->pixel_multiplier =
> +			((sdvox & SDVO_PORT_MULTIPLY_MASK)
> +			 >> SDVO_PORT_MULTIPLY_SHIFT) + 1;
> +	}
> +
> +	/* Cross check the port pixel multiplier with the sdvo encoder state. */
> +	intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_CLOCK_RATE_MULT, &val, 1);
> +	switch (val) {
> +	case SDVO_CLOCK_RATE_MULT_1X:
> +		encoder_pixel_multiplier = 1;
> +		break;
> +	case SDVO_CLOCK_RATE_MULT_2X:
> +		encoder_pixel_multiplier = 2;
> +		break;
> +	case SDVO_CLOCK_RATE_MULT_4X:
> +		encoder_pixel_multiplier = 4;
> +		break;
> +	}
> +	WARN(encoder_pixel_multiplier != pipe_config->pixel_multiplier,
> +	     "SDVO pixel multiplier mismatch, port: %i, encoder: %i\n",
> +	     pipe_config->pixel_multiplier, encoder_pixel_multiplier);
>  }

In intel_modeset_check_state() we call first encoder->get_config() and
only afterwards display->get_pipe_config(), so this won't work on
I915G/GM.

Other than that the 2 patches look ok:
Reviewed-by: Imre Deak <imre.deak@intel.com>

Related but not affecting my r-b:
The multiplier can take all values from 1-5, why aren't we handling all?
Should we add the proper check to intel_pipe_config_compare() too?

--Imre