Re: [Intel-gfx] [RFC PATCH 2/2] drm/i915/display: Add sleep for power state connector

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 15 Mar 2022, Vinod Govindapillai <vinod.govindapillai@intel.com> wrote:
> From: Mohammed Khajapasha <mohammed.khajapasha@intel.com>
>
> Add 2sec sleep for power state connector when a monitor
> is in power sleep state before atomic commit enable.

We're absolutely not adding a sleep like this.

> Monitors like LG 27UL650-W, 27UK850 goes into power
> sleep state and generates long duration hotplug events
> even the monitor connected for display, sleep for 2sec
> for power state monitor become available before enable
> atomic commit.

Again, will need a better description of the failure mode and/or a
detailed bug report to even suggest a better alternative.

BR,
Jani.

>
> Signed-off-by: Mohammed Khajapasha <mohammed.khajapasha@intel.com>
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 80 ++++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_display.h |  8 ++
>  2 files changed, 88 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 54db81c2cce6..a793f4234460 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -224,6 +224,81 @@ static int intel_compute_global_watermarks(struct intel_atomic_state *state)
>  	return 0;
>  }
>  
> +static void
> +intel_connectors_wakeup_hpd_suppress(struct intel_atomic_state *state)
> +{
> +	struct drm_i915_private *i915 = to_i915(state->base.dev);
> +	struct i915_hotplug *hpd = &i915->hotplug;
> +	bool do_delay = false;
> +	struct intel_connector *connector;
> +	struct intel_digital_connector_state *conn_state;
> +	int i;
> +
> +	if (!hpd->suppress_wakeup_hpd_enabled)
> +		return;
> +
> +	for_each_new_intel_connector_in_state(state, connector,
> +					      conn_state, i) {
> +		struct intel_crtc *crtc = to_intel_crtc(conn_state->base.crtc);
> +		struct intel_crtc_state *crtc_state;
> +
> +		if (!crtc || !intel_connector_needs_modeset(state,
> +							    &connector->base))
> +			continue;
> +
> +		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> +		if (!crtc_state->hw.active)
> +			continue;
> +
> +		if (!intel_connector_need_suppress_wakeup_hpd(connector))
> +			continue;
> +
> +		if (time_is_before_jiffies64(connector->disabled_time +
> +					     msecs_to_jiffies(MSEC_PER_SEC * 10))) {
> +			drm_dbg_kms(&i915->drm,
> +				    "[CONNECTOR:%d:%s] Suppress wakeup HPD for 2 secs\n",
> +				    connector->base.base.id, connector->base.name);
> +			do_delay = true;
> +		}
> +	}
> +
> +	if (do_delay)
> +		msleep(2 * MSEC_PER_SEC);
> +}
> +
> +static void
> +intel_connectors_wakeup_hpd_track_disabling(struct intel_atomic_state *state)
> +{
> +	struct drm_i915_private *i915 = to_i915(state->base.dev);
> +	struct i915_hotplug *hpd = &i915->hotplug;
> +	struct intel_connector *connector;
> +	struct intel_digital_connector_state *conn_state;
> +	int i;
> +
> +	if (!hpd->suppress_wakeup_hpd_enabled)
> +		return;
> +
> +	for_each_old_intel_connector_in_state(state, connector,
> +					      conn_state, i) {
> +		struct intel_crtc *crtc = to_intel_crtc(conn_state->base.crtc);
> +		struct intel_crtc_state *crtc_state;
> +
> +		if (!crtc || !intel_connector_needs_modeset(state,
> +							    &connector->base))
> +			continue;
> +
> +		crtc_state = intel_atomic_get_old_crtc_state(state, crtc);
> +		if (!crtc_state->hw.active)
> +			continue;
> +
> +		drm_dbg_kms(&i915->drm,
> +			    "[CONNECTOR:%d:%s] Update disabled time for wakeup HPD handling\n",
> +			    connector->base.base.id, connector->base.name);
> +
> +		connector->disabled_time = get_jiffies_64();
> +	}
> +}
> +
>  /* returns HPLL frequency in kHz */
>  int vlv_get_hpll_vco(struct drm_i915_private *dev_priv)
>  {
> @@ -8517,6 +8592,8 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>  		}
>  	}
>  
> +	intel_connectors_wakeup_hpd_track_disabling(state);
> +
>  	intel_commit_modeset_disables(state);
>  
>  	/* FIXME: Eventually get rid of our crtc->config pointer */
> @@ -8560,6 +8637,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>  	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
>  	dev_priv->display->commit_modeset_enables(state);
>  
> +	/* sleep for 2sec for power state connector become available */
> +	intel_connectors_wakeup_hpd_suppress(state);
> +
>  	intel_encoders_update_complete(state);
>  
>  	if (state->modeset)
> diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> index 8513703086b7..12ecf1497b07 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.h
> +++ b/drivers/gpu/drm/i915/display/intel_display.h
> @@ -539,6 +539,14 @@ enum hpd_pin {
>  			     ((connector) = to_intel_connector((__state)->base.connectors[__i].ptr), \
>  			     (new_connector_state) = to_intel_digital_connector_state((__state)->base.connectors[__i].new_state), 1))
>  
> +#define for_each_old_intel_connector_in_state(__state, connector, old_connector_state, __i) \
> +	for ((__i) = 0; \
> +		(__i) < (__state)->base.num_connector; \
> +		(__i)++) \
> +		for_each_if((__state)->base.connectors[__i].ptr && \
> +				((connector) = to_intel_connector((__state)->base.connectors[__i].ptr), \
> +				(old_connector_state) = to_intel_digital_connector_state((__state)->base.connectors[__i].old_state), 1))
> +
>  int intel_atomic_add_affected_planes(struct intel_atomic_state *state,
>  				     struct intel_crtc *crtc);
>  u8 intel_calc_active_pipes(struct intel_atomic_state *state,

-- 
Jani Nikula, Intel Open Source Graphics Center