[Intel-gfx] [PATCH 01/13] drm/i915/tc: Fix TypeC port init/resume time sanitization

[Jani Nikula]

On Thu, 23 Sep 2021, "Souza, Jose" <jose.souza at intel.com> wrote:
> On Tue, 2021-09-21 at 03:23 +0300, Imre Deak wrote:
>> Atm during driver loading and system resume TypeC ports are accessed
>> before their HW/SW state is synced. Move the TypeC port sanitization to
>> the encoder's sync_state hook to fix this.
>> 
>> Fixes: f9e76a6e68d3 ("drm/i915: Add an encoder hook to sanitize its state during init/resume")
>> Cc: José Roberto de Souza <jose.souza at intel.com>
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Signed-off-by: Imre Deak <imre.deak at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_ddi.c     |  8 +++++++-
>>  drivers/gpu/drm/i915/display/intel_display.c | 20 +++++---------------
>>  2 files changed, 12 insertions(+), 16 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
>> index bba0ab99836b1..c4ed4675f5791 100644
>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> @@ -3840,7 +3840,13 @@ void hsw_ddi_get_config(struct intel_encoder *encoder,
>>  static void intel_ddi_sync_state(struct intel_encoder *encoder,
>>  				 const struct intel_crtc_state *crtc_state)
>>  {
>> -	if (intel_crtc_has_dp_encoder(crtc_state))
>> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>> +	enum phy phy = intel_port_to_phy(i915, encoder->port);
>> +
>> +	if (intel_phy_is_tc(i915, phy))
>> +		intel_tc_port_sanitize(enc_to_dig_port(encoder));
>
> Okay at this point we will not have any mst encoder, so the check is not needed.
>
>> +
>> +	if (crtc_state && intel_crtc_has_dp_encoder(crtc_state))
>>  		intel_dp_sync_state(encoder, crtc_state);
>>  }
>>  
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>> index f6c0c595f6313..8547842935389 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -12194,18 +12194,16 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>>  	readout_plane_state(dev_priv);
>>  
>>  	for_each_intel_encoder(dev, encoder) {
>> +		struct intel_crtc_state *crtc_state = NULL;
>> +
>>  		pipe = 0;
>>  
>>  		if (encoder->get_hw_state(encoder, &pipe)) {
>> -			struct intel_crtc_state *crtc_state;
>> -
>>  			crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
>>  			crtc_state = to_intel_crtc_state(crtc->base.state);
>>  
>>  			encoder->base.crtc = &crtc->base;
>>  			intel_encoder_get_config(encoder, crtc_state);
>> -			if (encoder->sync_state)
>> -				encoder->sync_state(encoder, crtc_state);
>>  
>>  			/* read out to slave crtc as well for bigjoiner */
>>  			if (crtc_state->bigjoiner) {
>> @@ -12220,6 +12218,9 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>>  			encoder->base.crtc = NULL;
>>  		}
>>  
>> +		if (encoder->sync_state)
>> +			encoder->sync_state(encoder, crtc_state);
>
> Call sync_state() with a null crtc_state will cause a crash in gen11_dsi_sync_state().
>
> gen11_dsi_sync_state() is the only user of crtc_state but it only wants to know what is the pipe, maybe to be safer change the argument to enum pipe?

How would intel_ddi_sync_state() know when to call and not call
intel_dp_sync_state() then? If the encoder's disabled, you shouldn't do
that. That's the distinction NULL crtc_state gives (and obviously needs
to be taken into account).

BR,
Jani.


>
>> +
>>  		drm_dbg_kms(&dev_priv->drm,
>>  			    "[ENCODER:%d:%s] hw state readout: %s, pipe %c\n",
>>  			    encoder->base.base.id, encoder->base.name,
>> @@ -12502,17 +12503,6 @@ intel_modeset_setup_hw_state(struct drm_device *dev,
>>  	intel_modeset_readout_hw_state(dev);
>>  
>>  	/* HW state is read out, now we need to sanitize this mess. */
>> -
>> -	/* Sanitize the TypeC port mode upfront, encoders depend on this */
>> -	for_each_intel_encoder(dev, encoder) {
>> -		enum phy phy = intel_port_to_phy(dev_priv, encoder->port);
>> -
>> -		/* We need to sanitize only the MST primary port. */
>> -		if (encoder->type != INTEL_OUTPUT_DP_MST &&
>> -		    intel_phy_is_tc(dev_priv, phy))
>> -			intel_tc_port_sanitize(enc_to_dig_port(encoder));
>> -	}
>> -
>>  	get_encoder_power_domains(dev_priv);
>>  
>>  	if (HAS_PCH_IBX(dev_priv))
>

-- 
Jani Nikula, Intel Open Source Graphics Center