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

[Shankar, Uma]

> -----Original Message-----
> From: Gupta, Anshuman <anshuman.gupta at intel.com>
> Sent: Wednesday, March 18, 2020 5:37 PM
> To: Shankar, Uma <uma.shankar at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Khor, Swee Aun <swee.aun.khor at intel.com>
> Subject: Re: [Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset at boot for audio
> codec init
> 
> On 2020-03-18 at 17:00:09 +0530, Uma Shankar wrote:
> > 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;
> I would prefer to compute crtc_state->has_audio in compute_config at boot up  and
> then force a full modeset in intel_pipe_config_compare(), this way atomically we
> can force the full modeset on boot up.

Unfortunately the audio state is not yet detected here at bootup (read of EDID not yet done),
hence EDID data is not available. We tried to explore this path but this didn't worked out. We
forced modeset at intel_initial_commit but due to the above reason, things didn't worked out.

Regards,
Uma Shankar

> Thanks,
> Anshuman Gupta.
> >  	}
> >
> >  	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)
> > --
> > 2.22.0
> >
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