On Mon, Jan 22, 2018 at 12:07:28PM +0530, Sharma, Shashank wrote:
> Regards
>
> Shashank
>
>
> On 1/13/2018 2:34 AM, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > The LG 4k TV I have doesn't deassert HPD when I turn the TV off, but
> > when I turn it back on it will pulse the HPD line. By that time it has
> > forgotten everything we told it about scrambling and the clock ratio.
> > Hence if we want to get a picture out if it again we have to tell it
> > whether we're currently sending scrambled data or not. Implement
> > that via the encoder->hotplug() hook.
> >
> > v2: Force a full modeset to not follow the HDMI 2.0 spec more
> > closely (Shashank)
> >
> > Cc: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/intel_ddi.c | 146 ++++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 145 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index 1aeae3e97013..25793bdc692f 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -25,6 +25,7 @@
> > *
> > */
> >
> > +#include <drm/drm_scdc_helper.h>
> > #include "i915_drv.h"
> > #include "intel_drv.h"
> >
> > @@ -2756,6 +2757,146 @@ intel_ddi_init_dp_connector(struct intel_digital_port *intel_dig_port)
> > return connector;
> > }
> >
> > +static int modeset_pipe(struct drm_crtc *crtc,
> > + struct drm_modeset_acquire_ctx *ctx)
> Should this function go to intel_atomic.c or similar ?
Do you have another user for it? If not I don't see a particularly
good reason for moving it out.
> Also a little
> documentation about
> usage will be helpful for others, who want to reuse this.
What should it say? To me the function name is pretty clear.
> > +{
> > + struct drm_atomic_state *state;
> > + struct drm_crtc_state *crtc_state;
> > + int ret;
> > +
> > + state = drm_atomic_state_alloc(crtc->dev);
> > + if (!state)
> > + return -ENOMEM;
> > +
> > + state->acquire_ctx = ctx;
> > +
> > + crtc_state = drm_atomic_get_crtc_state(state, crtc);
> > + if (IS_ERR(crtc_state)) {
> > + ret = PTR_ERR(crtc_state);
> > + goto out;
> > + }
> > +
> > + crtc_state->mode_changed = true;
> > +
> > + ret = drm_atomic_add_affected_connectors(state, crtc);
> > + if (ret)
> > + goto out;
> > +
> > + ret = drm_atomic_add_affected_planes(state, crtc);
> > + if (ret)
> > + goto out;
> > +
> > + ret = drm_atomic_commit(state);
> > + if (ret)
> > + goto out;
> > +
> As this is an internal modeset trigger, should we send an event to
> userspace about this ?
What would userspace do with such an event?
> > + return 0;
> > +
> > + out:
> one debug message here telling us about if modeset was success/fail ?
There's a WARN already higher up.
> > + drm_atomic_state_put(state);
> > +
> > + return ret;
> > +}
> > +
> > +static int intel_hdmi_reset_link(struct intel_encoder *encoder,
> > + struct drm_modeset_acquire_ctx *ctx)
> > +{
> > + struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > + struct intel_hdmi *hdmi = enc_to_intel_hdmi(&encoder->base);
> > + struct intel_connector *connector = hdmi->attached_connector;
> > + struct i2c_adapter *adapter =
> > + intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
> > + struct drm_connector_state *conn_state;
> > + struct intel_crtc_state *crtc_state;
> > + struct intel_crtc *crtc;
> > + u8 config;
> > + int ret;
> > +
> > + if (!connector || connector->base.status != connector_status_connected)
> > + return 0;
> > +
> > + ret = drm_modeset_lock(&dev_priv->drm.mode_config.connection_mutex, ctx);
> > + if (ret)
> > + return ret;
> > +
> > + conn_state = connector->base.state;
> > +
> > + crtc = to_intel_crtc(conn_state->crtc);
> > + if (!crtc)
> > + return 0;
> > +
> > + ret = drm_modeset_lock(&crtc->base.mutex, ctx);
> > + if (ret)
> > + return ret;
> > +
> > + crtc_state = to_intel_crtc_state(crtc->base.state);
> > +
> > + WARN_ON(!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI));
> > +
> > + if (!crtc_state->base.active)
> > + return 0;
> > +
> > + if (!crtc_state->hdmi_high_tmds_clock_ratio &&
> > + !crtc_state->hdmi_scrambling)
> > + return 0;
> > +
> > + if (conn_state->commit &&
> > + !try_wait_for_completion(&conn_state->commit->hw_done))
> > + return 0;
> > +
> > + ret = drm_scdc_readb(adapter, SCDC_TMDS_CONFIG, &config);
> > + if (ret < 0) {
> > + DRM_ERROR("Failed to read TMDS config: %d\n", ret);
> > + return 0;
> > + }
> We can export this read as helper in scdc_helper.c, something like
> drm_scdc_get_tmds_clock_ratio ?
Feels like fairly pointless abstraction to me. And we'd either need
to do two SCDC reads instead of one, or return two things from said
function.
> - Shashank
> > +
> > + if (!!(config & SCDC_TMDS_BIT_CLOCK_RATIO_BY_40) ==
> > + crtc_state->hdmi_high_tmds_clock_ratio &&
> > + !!(config & SCDC_SCRAMBLING_ENABLE) ==
> > + crtc_state->hdmi_scrambling)
> > + return 0;
> > +
> > + /*
> > + * HDMI 2.0 says that one should not send scrambled data
> > + * prior to configuring the sink scrambling, and that
> > + * TMDS clock/data transmission should be suspended when
> > + * changing the TMDS clock rate in the sink. So let's
> > + * just do a full modeset here, even though some sinks
> > + * would be perfectly happy if were to just reconfigure
> > + * the SCDC settings on the fly.
> > + */
> > + return modeset_pipe(&crtc->base, ctx);
> > +}
> > +
> > +static bool intel_ddi_hotplug(struct intel_encoder *encoder,
> > + struct intel_connector *connector)
> > +{
> > + struct drm_modeset_acquire_ctx ctx;
> > + bool changed;
> > + int ret;
> > +
> > + changed = intel_encoder_hotplug(encoder, connector);
> > +
> > + drm_modeset_acquire_init(&ctx, 0);
> > +
> > + for (;;) {
> > + ret = intel_hdmi_reset_link(encoder, &ctx);
> > +
> > + if (ret == -EDEADLK) {
> > + drm_modeset_backoff(&ctx);
> > + continue;
> > + }
> > +
> > + break;
> > + }
> > +
> > + drm_modeset_drop_locks(&ctx);
> > + drm_modeset_acquire_fini(&ctx);
> > + WARN(ret, "Acquiring modeset locks failed with %i\n", ret);
> > +
> > + return changed;
> > +}
> > +
> > static struct intel_connector *
> > intel_ddi_init_hdmi_connector(struct intel_digital_port *intel_dig_port)
> > {
> > @@ -2866,7 +3007,10 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
> > drm_encoder_init(&dev_priv->drm, encoder, &intel_ddi_funcs,
> > DRM_MODE_ENCODER_TMDS, "DDI %c", port_name(port));
> >
> > - intel_encoder->hotplug = intel_encoder_hotplug;
> > + if (init_hdmi)
> > + intel_encoder->hotplug = intel_ddi_hotplug;
> > + else
> > + intel_encoder->hotplug = intel_encoder_hotplug;
> > intel_encoder->compute_output_type = intel_ddi_compute_output_type;
> > intel_encoder->compute_config = intel_ddi_compute_config;
> > intel_encoder->enable = intel_enable_ddi;
--
Ville Syrjälä
Intel OTC
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