On Fri, Mar 22, 2019 at 11:34:25AM +0200, Jani Nikula wrote:
> On Thu, 21 Mar 2019, Manasi Navare <manasi.d.navare@xxxxxxxxx> wrote:
> > 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.
> >
> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> > Signed-off-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/intel_display.c | 59 ++++++++++++++++++++++++++++
> > 1 file changed, 59 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 9980a4ed8c9c..16b46a3cb3bd 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -4009,6 +4009,62 @@ static void icl_set_pipe_chicken(struct intel_crtc *crtc)
> > I915_WRITE(PIPE_CHICKEN(pipe), tmp);
> > }
> >
> > +static void icl_set_transcoder_port_sync(struct intel_atomic_state *old_intel_state,
> > + 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);
> > + struct intel_crtc_state *genlock_crtc_state = NULL;
> > + enum transcoder genlock_transcoder;
> > + u32 trans_ddi_func_ctl2_val;
> > + u8 master_select;
> > +
> > + /*
> > + * Port Sync Mode cannot be enabled for DP MST
> > + */
> > + if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST))
> > + return;
> > +
> > + /*
> > + * Configure the master select and enable Transcoder Port Sync for
> > + * Slave CRTCs transcoder.
> > + */
> > + if (!crtc_state->genlock_crtc)
> > + return;
> > +
> > + genlock_crtc_state = intel_atomic_get_new_crtc_state(old_intel_state,
> > + crtc_state->genlock_crtc);
> > + if (WARN_ON(!genlock_crtc_state))
> > + return;
> > +
> > + genlock_transcoder = genlock_crtc_state->cpu_transcoder;
> > + switch (genlock_transcoder) {
> > + case TRANSCODER_A:
> > + master_select = 1;
> > + break;
> > + case TRANSCODER_B:
> > + master_select = 2;
> > + break;
> > + case TRANSCODER_C:
> > + master_select = 3;
> > + break;
> > + case TRANSCODER_EDP:
> > + default:
> > + master_select = 0;
> > + break;
> > + }
> > + /* Set the master select bits for Tranascoder Port Sync */
> > + trans_ddi_func_ctl2_val = I915_READ(TRANS_DDI_FUNC_CTL2(crtc_state->cpu_transcoder));
> > + trans_ddi_func_ctl2_val |= (PORT_SYNC_MODE_MASTER_SELECT(master_select) &
> > + PORT_SYNC_MODE_MASTER_SELECT_MASK) <<
> > + PORT_SYNC_MODE_MASTER_SELECT_SHIFT;
>
> This doesn't do what you think it does. ITYM,
>
> val = I915_READ();
> val &= ~FOO_MASK;
> val |= FOO_BAR;
Also we alreayd have a place where we write this registers. Is there
some magic requirement why these bits can't be set there along with
eveyrthing else?
>
> Please actually use just "val" for the variable, the long name just
> makes this all harder to read.
>
> BR,
> Jani.
>
>
> > + /* 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)
> > {
> > @@ -5960,6 +6016,9 @@ 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_set_transcoder_port_sync(old_intel_state, pipe_config);
> > +
> > intel_set_pipe_src_size(pipe_config);
> >
> > if (cpu_transcoder != TRANSCODER_EDP &&
>
> --
> Jani Nikula, Intel Open Source Graphics Center
--
Ville Syrjälä
Intel
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