Re: [PATCH 4/5] drm/i915/psr: Control PSR interrupts via debugfs

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

On Tue, Mar 20, 2018 at 03:41:50PM -0700, Dhinakaran Pandiyan wrote:
> Interrupts other than the one for AUX errors are required only for debug,
> so unmask them via debugfs when the user requests debug.
> 
> User can make such a request with
> echo 1 > <DEBUG_FS>/dri/0/i915_edp_psr_debug
> 
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter@intel.com>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 36 +++++++++++++++++++-
>  drivers/gpu/drm/i915/i915_drv.h     |  1 +
>  drivers/gpu/drm/i915/i915_irq.c     | 68 ++++++++++++++++---------------------
>  drivers/gpu/drm/i915/intel_drv.h    |  2 ++
>  drivers/gpu/drm/i915/intel_psr.c    | 56 ++++++++++++++++++++++++++++++
>  5 files changed, 123 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 964ea1a12357..669f3d56054a 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2690,6 +2690,39 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
>  	return 0;
>  }
>  
> +static int
> +i915_edp_psr_debug_set(void *data, u64 val)
> +{
> +	struct drm_i915_private *dev_priv = data;
> +
> +	if (!CAN_PSR(dev_priv))
> +		return -ENODEV;
> +
> +	if (val < 0  || val > 1)
> +		return -EINVAL;
> +
> +	DRM_DEBUG_KMS("%s PSR debug\n", val == 1 ? "Enabling" : "Disabling");
> +	intel_psr_debug_control(dev_priv, val);
> +
> +	return 0;
> +}
> +
> +static int
> +i915_edp_psr_debug_get(void *data, u64 *val)
> +{
> +	struct drm_i915_private *dev_priv = data;
> +
> +	if (!CAN_PSR(dev_priv))
> +		return -ENODEV;
> +
> +	*val = READ_ONCE(dev_priv->psr.debug);
> +	return 0;
> +}
> +
> +DEFINE_SIMPLE_ATTRIBUTE(i915_edp_psr_debug_fops,
> +			i915_edp_psr_debug_get, i915_edp_psr_debug_set,
> +			"%llu\n");
> +
>  static int i915_sink_crc(struct seq_file *m, void *data)
>  {
>  	struct drm_i915_private *dev_priv = node_to_i915(m->private);
> @@ -4811,7 +4844,8 @@ static const struct i915_debugfs_files {
>  	{"i915_guc_log_relay", &i915_guc_log_relay_fops},
>  	{"i915_hpd_storm_ctl", &i915_hpd_storm_ctl_fops},
>  	{"i915_ipc_status", &i915_ipc_status_fops},
> -	{"i915_drrs_ctl", &i915_drrs_ctl_fops}
> +	{"i915_drrs_ctl", &i915_drrs_ctl_fops},
> +	{"i915_edp_psr_debug", &i915_edp_psr_debug_fops}
>  };
>  
>  int i915_debugfs_register(struct drm_i915_private *dev_priv)
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index e27ba8fb64e6..136fa2267a66 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -608,6 +608,7 @@ struct i915_psr {
>  	bool colorimetry_support;
>  	bool alpm;
>  	bool has_hw_tracking;
> +	bool debug;
>  
>  	void (*enable_source)(struct intel_dp *,
>  			      const struct intel_crtc_state *);
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 56228e8ed980..94941b52f1cf 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -2392,40 +2392,6 @@ static void ilk_display_irq_handler(struct drm_i915_private *dev_priv,
>  		ironlake_rps_change_irq_handler(dev_priv);
>  }
>  
> -static void hsw_edp_psr_irq_handler(struct drm_i915_private *dev_priv)
> -{
> -	u32 edp_psr_iir = I915_READ(EDP_PSR_IIR);
> -	u32 edp_psr_imr = I915_READ(EDP_PSR_IMR);
> -	u32 mask = BIT(TRANSCODER_EDP);
> -	enum transcoder cpu_transcoder;
> -
> -	if (INTEL_GEN(dev_priv) >= 8)
> -		mask |= BIT(TRANSCODER_A) |
> -			BIT(TRANSCODER_B) |
> -			BIT(TRANSCODER_C);
> -
> -	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, mask) {
> -		if (edp_psr_iir & EDP_PSR_ERROR(cpu_transcoder))
> -			DRM_DEBUG_KMS("Transcoder %s PSR error\n",
> -				      transcoder_name(cpu_transcoder));
> -
> -		if (edp_psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder)) {
> -			DRM_DEBUG_KMS("Transcoder %s PSR prepare entry in 2 vblanks\n",
> -				      transcoder_name(cpu_transcoder));
> -			edp_psr_imr |= EDP_PSR_PRE_ENTRY(cpu_transcoder);
> -		}
> -
> -		if (edp_psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder)) {
> -			DRM_DEBUG_KMS("Transcoder %s PSR exit completed\n",
> -				      transcoder_name(cpu_transcoder));
> -			edp_psr_imr &= ~EDP_PSR_PRE_ENTRY(cpu_transcoder);
> -		}
> -	}
> -
> -	I915_WRITE(EDP_PSR_IMR, edp_psr_imr);
> -	I915_WRITE(EDP_PSR_IIR, edp_psr_iir);
> -}
> -
>  static void ivb_display_irq_handler(struct drm_i915_private *dev_priv,
>  				    u32 de_iir)
>  {
> @@ -2438,8 +2404,12 @@ static void ivb_display_irq_handler(struct drm_i915_private *dev_priv,
>  	if (de_iir & DE_ERR_INT_IVB)
>  		ivb_err_int_handler(dev_priv);
>  
> -	if (de_iir & DE_EDP_PSR_INT_HSW)
> -		hsw_edp_psr_irq_handler(dev_priv);
> +	if (de_iir & DE_EDP_PSR_INT_HSW) {
> +		u32 psr_iir = I915_READ(EDP_PSR_IIR);
> +
> +		intel_psr_irq_handler(dev_priv, psr_iir);
> +		I915_WRITE(EDP_PSR_IIR, psr_iir);
> +	}
>  
>  	if (de_iir & DE_AUX_CHANNEL_A_IVB)
>  		dp_aux_irq_handler(dev_priv);
> @@ -2581,7 +2551,10 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
>  			}
>  
>  			if (iir & GEN8_DE_EDP_PSR) {
> -				hsw_edp_psr_irq_handler(dev_priv);
> +				u32 psr_iir = I915_READ(EDP_PSR_IIR);
> +
> +				intel_psr_irq_handler(dev_priv, psr_iir);
> +				I915_WRITE(EDP_PSR_IIR, psr_iir);
>  				found = true;
>  			}
>  
> @@ -3699,6 +3672,23 @@ static void gen5_gt_irq_postinstall(struct drm_device *dev)
>  	}
>  }
>  
> +static inline u32 psr_mask(struct drm_i915_private *dev_priv)
> +{
> +	u32 transcoders = BIT(TRANSCODER_EDP);
> +	u32 mask = 0;
> +	enum transcoder cpu_transcoder;
> +
> +	if (INTEL_GEN(dev_priv) >= 8)
> +		transcoders |= BIT(TRANSCODER_A) |
> +			       BIT(TRANSCODER_B) |
> +			       BIT(TRANSCODER_C);
> +
> +	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders)
> +		mask |=  EDP_PSR_ERROR(cpu_transcoder);
> +
> +	return ~mask;
> +}
> +
>  static int ironlake_irq_postinstall(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> @@ -3721,7 +3711,7 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
>  
>  	if (IS_HASWELL(dev_priv)) {
>  		gen3_assert_iir_is_zero(dev_priv, EDP_PSR_IIR);
> -		I915_WRITE(EDP_PSR_IMR, 0);
> +		I915_WRITE(EDP_PSR_IMR, psr_mask(dev_priv));
>  		display_mask |= DE_EDP_PSR_INT_HSW;
>  	}
>  
> @@ -3861,7 +3851,7 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
>  		de_port_enables |= GEN8_PORT_DP_A_HOTPLUG;
>  
>  	gen3_assert_iir_is_zero(dev_priv, EDP_PSR_IIR);
> -	I915_WRITE(EDP_PSR_IMR, 0);
> +	I915_WRITE(EDP_PSR_IMR, psr_mask(dev_priv));

psr_mask() seems somewhat pointless to me. Could perhaps just
write the full mask by hand in these cases.

>  
>  	for_each_pipe(dev_priv, pipe) {
>  		dev_priv->de_irq_mask[pipe] = ~de_pipe_masked;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a215aa78b0be..8be75cc5bf24 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1887,6 +1887,8 @@ void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
>  				   unsigned frontbuffer_bits);
>  void intel_psr_compute_config(struct intel_dp *intel_dp,
>  			      struct intel_crtc_state *crtc_state);
> +void intel_psr_debug_control(struct drm_i915_private *dev_priv, bool enable);
> +void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir);
>  
>  /* intel_runtime_pm.c */
>  int intel_power_domains_init(struct drm_i915_private *);
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index 317cb4a12693..64ecea80438d 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -93,6 +93,62 @@ static void psr_aux_io_power_put(struct intel_dp *intel_dp)
>  	intel_display_power_put(dev_priv, psr_aux_domain(intel_dp));
>  }
>  
> +void intel_psr_debug_control(struct drm_i915_private *dev_priv, bool enable)
> +{
> +	u32 transcoders = BIT(TRANSCODER_EDP);
> +	u32 mask = 0;
> +	enum transcoder cpu_transcoder;
> +
> +	/* No PSR interrupts on VLV/CHV */
> +	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> +		return;
> +
> +	if (INTEL_GEN(dev_priv) >= 8)
> +		transcoders |= BIT(TRANSCODER_A) |
> +			       BIT(TRANSCODER_B) |
> +			       BIT(TRANSCODER_C);
> +
> +	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders)
> +		mask = EDP_PSR_POST_EXIT(cpu_transcoder) |
> +		       EDP_PSR_PRE_ENTRY(cpu_transcoder);

This too could be done w/o the loop I think.

> +
> +	if (enable) {
> +		WRITE_ONCE(dev_priv->psr.debug, true);
> +		I915_WRITE(EDP_PSR_IMR, ~mask);
> +	} else {
> +		I915_WRITE(EDP_PSR_IMR, mask);
> +		WRITE_ONCE(dev_priv->psr.debug, false);
> +	}
> +}
> +
> +void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
> +{
> +	u32 transcoders = BIT(TRANSCODER_EDP);
> +	enum transcoder cpu_transcoder;
> +
> +	if (INTEL_GEN(dev_priv) >= 8)
> +		transcoders |= BIT(TRANSCODER_A) |
> +			       BIT(TRANSCODER_B) |
> +			       BIT(TRANSCODER_C);
> +
> +	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders) {
> +		/* FIXME: Exit PSR when this happens. */
> +		if (psr_iir & EDP_PSR_ERROR(cpu_transcoder))
> +			DRM_DEBUG_KMS("[transcoder %s] PSR aux error\n",
> +				      transcoder_name(cpu_transcoder));
> +
> +		if (psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder)) {
> +			DRM_DEBUG_KMS("[transcoder %s] PSR entry in 2 vblanks\n",
> +				      transcoder_name(cpu_transcoder));
> +		}
> +
> +		if (psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder)) {
> +			DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
> +				      transcoder_name(cpu_transcoder));
> +		}
> +	}
> +}
> +
>  static bool intel_dp_get_y_cord_status(struct intel_dp *intel_dp)
>  {
>  	uint8_t psr_caps = 0;
> -- 
> 2.14.1

-- 
Ville Syrjälä
Intel OTC
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