[Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init

[Shankar, Uma]

> -----Original Message-----
> From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Sent: Wednesday, March 18, 2020 5:46 PM
> To: Shankar, Uma <uma.shankar at intel.com>; intel-gfx at lists.freedesktop.org
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>; Kai Vehmanen
> <kai.vehmanen at linux.intel.com>; Khor, Swee Aun <swee.aun.khor at intel.com>
> Subject: Re: [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init
> 
> Op 18-03-2020 om 12:30 schreef Uma Shankar:
> > If external monitors are connected during boot up, driver uses the
> > same mode programmed by BIOS and avoids a full modeset.
> > This results in display audio codec left uninitialized and display
> > audio fails to work till user triggers a modeset.
> >
> > This patch fixes the same by triggering a modeset at boot.
> >
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Kai Vehmanen <kai.vehmanen at linux.intel.com>
> > Signed-off-by: Uma Shankar <uma.shankar at intel.com>
> > Signed-off-by: SweeAun Khor <swee.aun.khor at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_ddi.c     | 4 ++++
> >  drivers/gpu/drm/i915/display/intel_display.c | 8 ++++++++
> >  drivers/gpu/drm/i915/i915_drv.h              | 3 +++
> >  3 files changed, 15 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 73d0f4648c06..ba380afa73a6 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -3704,6 +3704,10 @@ static void intel_ddi_update_pipe(struct intel_encoder
> *encoder,
> >  				  const struct intel_crtc_state *crtc_state,
> >  				  const struct drm_connector_state *conn_state)  {
> > +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > +
> > +	/* Clear the bootflag */
> > +	dev_priv->bootflag = false;
> >
> >  	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
> >  		intel_ddi_update_pipe_dp(encoder, crtc_state, conn_state); diff
> > --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index 8f23c4d51c33..a1487539495f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -14751,6 +14751,10 @@ static int intel_atomic_check(struct drm_device
> *dev,
> >  		if (new_crtc_state->hw.mode.private_flags !=
> >  		    old_crtc_state->hw.mode.private_flags)
> >  			new_crtc_state->uapi.mode_changed = true;
> > +
> > +		/* Set mode_change to init audio code once at boot */
> > +		if (dev_priv->bootflag && new_crtc_state->hw.active)
> > +			new_crtc_state->uapi.mode_changed = true;
> >  	}
> >
> >  	ret = drm_atomic_helper_check_modeset(dev, &state->base); @@
> > -17655,11 +17659,15 @@ static void intel_update_fdi_pll_freq(struct
> > drm_i915_private *dev_priv)
> >
> >  static int intel_initial_commit(struct drm_device *dev)  {
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> >  	struct drm_atomic_state *state = NULL;
> >  	struct drm_modeset_acquire_ctx ctx;
> >  	struct intel_crtc *crtc;
> >  	int ret = 0;
> >
> > +	/* Set Flag to trigger modeset for audio codec init */
> > +	dev_priv->bootflag = true;
> > +
> >  	state = drm_atomic_state_alloc(dev);
> >  	if (!state)
> >  		return -ENOMEM;
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index a7ea1d855359..207196f9632b
> > 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -1210,6 +1210,9 @@ struct drm_i915_private {
> >  	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
> >  	 * will be rejected. Instead look for a better place.
> >  	 */
> > +
> > +	/* Flag to trigger modeset for Audio codec init once during boot */
> > +	bool bootflag;
> >  };
> >
> >  static inline struct drm_i915_private *to_i915(const struct
> > drm_device *dev)
> 
> This is not going to help. We read out the has_audio flag now, the only thing we miss
> is to enable the audio codec. This should be done after the first detect(), in the
> manner which I described to get the correct eld values.

Hi Maarten,
At the time of sanitize, we don't have edid so has_audio flag will not be set. Also codec_enable
needs encoder, crtc_state, conn_state. All these are not there as part of detect callbacks.

With current approach, we force a modeset just during boot and then reset the flag so that normal
operations don't get affected.

Regards,
Uma Shankar

> ~Maarten