Re: [PATCH] drm/i915: Make CHICKEN_TRANS reg not depend on enum value

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

On Mon, 19 Nov 2018, Imre Deak <imre.deak@intel.com> wrote:
> Depending on the transcoder enum values to translate from transcoder to the
> corresponding CHICKEN_TRANS register can easily break if we add a new
> transcoder. Add an explicit mapping instead, by using helpers to look up the
> register instance either by transcoder or port (since unconveniently the
> registers have both port and transcoder specific bits).
>
> While at it also check for the correctness of GEN, port, transcoder. I wasn't
> sure if psr2_enabled can only be set for GEN9+, but that seems to be the case
> indeed (see setting of sink_psr2_support in intel_psr_init_dpcd()).
>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: Mika Kahola <mika.kahola@intel.com>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  |  7 +++---
>  drivers/gpu/drm/i915/intel_ddi.c | 53 +++++++++++++++++++++++++++++++---------
>  drivers/gpu/drm/i915/intel_drv.h |  2 ++
>  drivers/gpu/drm/i915/intel_psr.c |  6 +++--
>  4 files changed, 51 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 25b069175c2a..1beed39de303 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7399,9 +7399,10 @@ enum {
>  #define  BDW_DPRS_MASK_VBLANK_SRD	(1 << 0)
>  #define CHICKEN_PIPESL_1(pipe) _MMIO_PIPE(pipe, _CHICKEN_PIPESL_1_A, _CHICKEN_PIPESL_1_B)
>  
> -#define CHICKEN_TRANS_A         0x420c0
> -#define CHICKEN_TRANS_B         0x420c4
> -#define CHICKEN_TRANS(trans) _MMIO_TRANS(trans, CHICKEN_TRANS_A, CHICKEN_TRANS_B)
> +#define CHICKEN_TRANS_A		_MMIO(0x420c0)
> +#define CHICKEN_TRANS_B		_MMIO(0x420c4)
> +#define CHICKEN_TRANS_C		_MMIO(0x420c8)
> +#define CHICKEN_TRANS_EDP	_MMIO(0x420cc)
>  #define  VSC_DATA_SEL_SOFTWARE_CONTROL	(1 << 25) /* GLK and CNL+ */
>  #define  DDI_TRAINING_OVERRIDE_ENABLE	(1 << 19)
>  #define  DDI_TRAINING_OVERRIDE_VALUE	(1 << 18)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 040483c96029..126e6aac335d 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -3380,6 +3380,42 @@ static void intel_enable_ddi_dp(struct intel_encoder *encoder,
>  		intel_audio_codec_enable(encoder, crtc_state, conn_state);
>  }
>  
> +i915_reg_t gen9_chicken_trans_reg(struct drm_i915_private *dev_priv,
> +				  enum transcoder trans)
> +{
> +	static const i915_reg_t regs[] = {
> +		[TRANSCODER_A] = CHICKEN_TRANS_A,
> +		[TRANSCODER_B] = CHICKEN_TRANS_B,
> +		[TRANSCODER_C] = CHICKEN_TRANS_C,
> +		[TRANSCODER_EDP] = CHICKEN_TRANS_EDP,
> +	};
> +
> +	WARN_ON(INTEL_GEN(dev_priv) < 9);
> +
> +	if (WARN_ON(trans >= ARRAY_SIZE(regs) || !regs[trans].reg))
> +		trans = TRANSCODER_A;
> +
> +	return regs[trans];
> +}

I'm late to the party, but it kind of makes me sad that we're now
introducing yet another way to choose registers based on transcoder (or
some other index). And this one is hand-rolled, with local functions
instead of putting it to i915_reg.h.

BR,
Jani.


> +
> +static i915_reg_t
> +gen9_chicken_trans_reg_by_port(struct drm_i915_private *dev_priv,
> +			       enum port port)
> +{
> +	static const enum transcoder port_to_transcoder[] = {
> +		[PORT_A] = TRANSCODER_EDP,
> +		[PORT_B] = TRANSCODER_A,
> +		[PORT_C] = TRANSCODER_B,
> +		[PORT_D] = TRANSCODER_C,
> +		[PORT_E] = TRANSCODER_A,
> +	};
> +
> +	if (WARN_ON(port < PORT_A || port > PORT_E))
> +		port = PORT_A;
> +
> +	return gen9_chicken_trans_reg(dev_priv, port_to_transcoder[port]);
> +}
> +
>  static void intel_enable_ddi_hdmi(struct intel_encoder *encoder,
>  				  const struct intel_crtc_state *crtc_state,
>  				  const struct drm_connector_state *conn_state)
> @@ -3403,17 +3439,10 @@ static void intel_enable_ddi_hdmi(struct intel_encoder *encoder,
>  		 * the bits affect a specific DDI port rather than
>  		 * a specific transcoder.
>  		 */
> -		static const enum transcoder port_to_transcoder[] = {
> -			[PORT_A] = TRANSCODER_EDP,
> -			[PORT_B] = TRANSCODER_A,
> -			[PORT_C] = TRANSCODER_B,
> -			[PORT_D] = TRANSCODER_C,
> -			[PORT_E] = TRANSCODER_A,
> -		};
> -		enum transcoder transcoder = port_to_transcoder[port];
> +		i915_reg_t reg = gen9_chicken_trans_reg_by_port(dev_priv, port);
>  		u32 val;
>  
> -		val = I915_READ(CHICKEN_TRANS(transcoder));
> +		val = I915_READ(reg);
>  
>  		if (port == PORT_E)
>  			val |= DDIE_TRAINING_OVERRIDE_ENABLE |
> @@ -3422,8 +3451,8 @@ static void intel_enable_ddi_hdmi(struct intel_encoder *encoder,
>  			val |= DDI_TRAINING_OVERRIDE_ENABLE |
>  				DDI_TRAINING_OVERRIDE_VALUE;
>  
> -		I915_WRITE(CHICKEN_TRANS(transcoder), val);
> -		POSTING_READ(CHICKEN_TRANS(transcoder));
> +		I915_WRITE(reg, val);
> +		POSTING_READ(reg);
>  
>  		udelay(1);
>  
> @@ -3434,7 +3463,7 @@ static void intel_enable_ddi_hdmi(struct intel_encoder *encoder,
>  			val &= ~(DDI_TRAINING_OVERRIDE_ENABLE |
>  				 DDI_TRAINING_OVERRIDE_VALUE);
>  
> -		I915_WRITE(CHICKEN_TRANS(transcoder), val);
> +		I915_WRITE(reg, val);
>  	}
>  
>  	/* In HDMI/DVI mode, the port width, and swing/emphasis values
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index f575ba2a59da..0d064b71002b 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1526,6 +1526,8 @@ void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder);
>  
>  unsigned int intel_fb_align_height(const struct drm_framebuffer *fb,
>  				   int color_plane, unsigned int height);
> +i915_reg_t gen9_chicken_trans_reg(struct drm_i915_private *dev_priv,
> +				  enum transcoder trans);
>  
>  /* intel_audio.c */
>  void intel_init_audio_hooks(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index 5fdc2f196045..b4d811c62473 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -606,7 +606,9 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
>  		hsw_psr_setup_aux(intel_dp);
>  
>  	if (dev_priv->psr.psr2_enabled) {
> -		u32 chicken = I915_READ(CHICKEN_TRANS(cpu_transcoder));
> +		i915_reg_t reg = gen9_chicken_trans_reg(dev_priv,
> +							cpu_transcoder);
> +		u32 chicken = I915_READ(reg);
>  
>  		if (IS_GEN9(dev_priv) && !IS_GEMINILAKE(dev_priv))
>  			chicken |= (PSR2_VSC_ENABLE_PROG_HEADER
> @@ -614,7 +616,7 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
>  
>  		else
>  			chicken &= ~VSC_DATA_SEL_SOFTWARE_CONTROL;
> -		I915_WRITE(CHICKEN_TRANS(cpu_transcoder), chicken);
> +		I915_WRITE(reg, chicken);
>  	}
>  
>  	/*

-- 
Jani Nikula, Intel Open Source Graphics Center
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