[Intel-gfx] [PATCH 2/6] drm/i915/display/icl: Enable TRANSCODER PORT SYNC for tiled displays across separate ports

[Manasi Navare]

On Tue, Sep 17, 2019 at 04:52:54PM +0200, Maarten Lankhorst wrote:
> Op 09-09-2019 om 05:43 schreef Manasi Navare:
> > In case of tiled displays where different tiles are displayed across
> > different ports, we need to synchronize the transcoders involved.
> > This patch implements the transcoder port sync feature for
> > synchronizing one master transcoder with one or more slave
> > transcoders. This is only enbaled in slave transcoder
> > and the master transcoder is unaware that it is operating
> > in this mode.
> > This has been tested with tiled display connected to ICL.
> >
> > v4:
> > Rebase
> > v3:
> > * Check of DP_MST moved to atomic_check (Maarten)
> > v2:
> > * Do not use RMW, just write to the register in commit (Jani N)
> >
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Matt Roper <matthew.d.roper at intel.com>
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 43 ++++++++++++++++++++
> >  1 file changed, 43 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index 8942c905ae66..b8f7a919b6d3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -4380,6 +4380,46 @@ static void icl_set_pipe_chicken(struct intel_crtc *crtc)
> >  	I915_WRITE(PIPE_CHICKEN(pipe), tmp);
> >  }
> >  
> > +static void icl_enable_trans_port_sync(const struct intel_crtc_state *crtc_state)
> > +{
> > +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> > +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > +	u32 trans_ddi_func_ctl2_val;
> > +	u8 master_select;
> > +
> > +	/*
> > +	 * Configure the master select and enable Transcoder Port Sync for
> > +	 * Slave CRTCs transcoder.
> > +	 */
> > +	if (crtc_state->master_transcoder == INVALID_TRANSCODER)
> > +		return;
> > +
> > +	switch (crtc_state->master_transcoder) {
> > +	case TRANSCODER_A:
> > +		master_select = 1;
> > +		break;
> > +	case TRANSCODER_B:
> > +		master_select = 2;
> > +		break;
> > +	case TRANSCODER_C:
> > +		master_select = 3;
> > +		break;
> TRANSCODER_D btw?

Yes will add that

Manasi

> > +	case TRANSCODER_EDP:
> > +	default:
> > +		master_select = 0;
> > +		break;
> > +	}
> > +	/* Set the master select bits for Tranascoder Port Sync */
> > +	trans_ddi_func_ctl2_val = (PORT_SYNC_MODE_MASTER_SELECT(master_select) &
> > +				   PORT_SYNC_MODE_MASTER_SELECT_MASK) <<
> > +		PORT_SYNC_MODE_MASTER_SELECT_SHIFT;
> > +	/* Enable Transcoder Port Sync */
> > +	trans_ddi_func_ctl2_val |= PORT_SYNC_MODE_ENABLE;
> > +
> > +	I915_WRITE(TRANS_DDI_FUNC_CTL2(crtc_state->cpu_transcoder),
> > +		   trans_ddi_func_ctl2_val);
> > +}
> > +
> >  static void intel_update_pipe_config(const struct intel_crtc_state *old_crtc_state,
> >  				     const struct intel_crtc_state *new_crtc_state)
> >  {
> > @@ -6448,6 +6488,9 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
> >  	if (!transcoder_is_dsi(cpu_transcoder))
> >  		intel_set_pipe_timings(pipe_config);
> >  
> > +	if (INTEL_GEN(dev_priv) >= 11)
> > +		icl_enable_trans_port_sync(pipe_config);
> > +
> >  	intel_set_pipe_src_size(pipe_config);
> >  
> >  	if (cpu_transcoder != TRANSCODER_EDP &&
> 
>