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Message-ID: <1524610338.24461.35.camel@dk-H97M-D3H>
Subject: Re: [Intel-gfx] [PATCH v7 02/10] drm/i915: Move DP modeset retry
 work into intel_dp
From:   Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reply-To: dhinakaran.pandiyan@intel.com
To:     Lyude Paul <lyude@redhat.com>
Cc:     intel-gfx@lists.freedesktop.org, David Airlie <airlied@linux.ie>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= 
        <ville.syrjala@linux.intel.com>
Date:   Tue, 24 Apr 2018 15:52:18 -0700
In-Reply-To: <20180411225501.26751-3-lyude@redhat.com>
References: <20180411225501.26751-1-lyude@redhat.com>
         <20180411225501.26751-3-lyude@redhat.com>
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On Wed, 2018-04-11 at 18:54 -0400, Lyude Paul wrote:
> While having the modeset_retry_work in intel_connector makes sense with
> SST, this paradigm doesn't make a whole ton of sense when it comes to
> MST since we have to deal with multiple connectors. In most cases, it's
> more useful to just use the intel_dp struct since it indicates whether
> or not we're dealing with an MST device, along with being able to easily
> trace the intel_dp struct back to it's respective connector (if there is
> any). So, move the modeset_retry_work function out of the
> intel_connector struct and into intel_dp.
> 
> Signed-off-by: Lyude Paul <lyude@redhat.com>
> Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
> Cc: Manasi Navare <manasi.d.navare@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> V2:
>  - Remove accidental duplicate modeset_retry_work in intel_connector
> V3:
>  - Also check against eDP in intel_hpd_poll_fini() - mdnavare

contradicts with 

commit c0cfb10d9e1de490e36d3b9d4228c0ea0ca30677
Author: Manasi Navare <manasi.d.navare@intel.com>
Date:   Thu Oct 12 12:13:38 2017 -0700

    drm/i915/edp: Do not do link training fallback or prune modes on EDP

    In case of eDP because the panel has a fixed mode, the link rate
    and lane count at which it is trained corresponds to the link BW
    required to support the native resolution of the panel. In case of
    panles with lower resolutions where fewer lanes are hooked up
internally,
    that number is reflected in the MAX_LANE_COUNT DPCD register of the
panel.
    So it is pointless to fallback to lower link rate/lane count in case
    of link training failure on eDP connector since the lower link BW
    will not support the native resolution of the panel and we cannot
    prune the preferred mode on the eDP connector.


> V4:
>  - Don't bother looping over connectors for canceling modeset rety work,
>    just encoders.
> V7:
>  - Fix CHECKPATCH errors
> Signed-off-by: Lyude Paul <lyude@redhat.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c          | 14 +++++++++++---
>  drivers/gpu/drm/i915/intel_dp.c               | 10 ++++------
>  drivers/gpu/drm/i915/intel_dp_link_training.c |  2 +-
>  drivers/gpu/drm/i915/intel_drv.h              |  6 +++---
>  4 files changed, 19 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index e04050ea3e28..18edb9628a54 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -15471,20 +15471,28 @@ void intel_connector_unregister(struct drm_connector *connector)
>  
>  static void intel_hpd_poll_fini(struct drm_device *dev)
>  {
> -	struct intel_connector *connector;
>  	struct drm_connector_list_iter conn_iter;
> +	struct intel_connector *connector;
> +	struct intel_encoder *encoder;
> +	struct intel_dp *intel_dp;
>  
>  	/* Kill all the work that may have been queued by hpd. */
>  	drm_connector_list_iter_begin(dev, &conn_iter);
>  	for_each_intel_connector_iter(connector, &conn_iter) {
> -		if (connector->modeset_retry_work.func)
> -			cancel_work_sync(&connector->modeset_retry_work);
>  		if (connector->hdcp_shim) {
>  			cancel_delayed_work_sync(&connector->hdcp_check_work);
>  			cancel_work_sync(&connector->hdcp_prop_work);
>  		}
>  	}
>  	drm_connector_list_iter_end(&conn_iter);
> +
> +	for_each_intel_encoder(dev, encoder) {
> +		if (encoder->type == INTEL_OUTPUT_DP ||

commit 7e732cacb1ae27b2eb6902cabd93e9da086c54f0
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Fri Oct 27 22:31:24 2017 +0300

    drm/i915: Stop frobbing with DDI encoder->type

    Currently the DDI encoder->type will change at runtime depending on
    what kind of hotplugs we've processed. That's quite bad since we
can't
    really trust that that current value of encoder->type actually
matches
    the type of signal we're trying to drive through it.

    Let's eliminate that problem by declaring that non-eDP DDI port will
    always have the encoder type as INTEL_OUTPUT_DDI. This means the
code
    can no longer try to distinguish DP vs. HDMI based on encoder->type.
    We'll leave eDP as INTEL_OUTPUT_EDP, since it'll never change and
    there's a bunch of code that relies on that value to identify eDP
    encoders.


> +		    encoder->type == INTEL_OUTPUT_EDP) {
> +			intel_dp = enc_to_intel_dp(&encoder->base);
> +			cancel_work_sync(&intel_dp->modeset_retry_work);
> +		}
> +	}
>  }
>  
>  void intel_modeset_cleanup(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 62f82c4298ac..fbb467bc227d 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -6249,12 +6249,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  
>  static void intel_dp_modeset_retry_work_fn(struct work_struct *work)
>  {
> -	struct intel_connector *intel_connector;
> -	struct drm_connector *connector;
> +	struct intel_dp *intel_dp = container_of(work, typeof(*intel_dp),
> +						 modeset_retry_work);
> +	struct drm_connector *connector = &intel_dp->attached_connector->base;
>  
> -	intel_connector = container_of(work, typeof(*intel_connector),
> -				       modeset_retry_work);
> -	connector = &intel_connector->base;
>  	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
>  		      connector->name);
>  
> @@ -6283,7 +6281,7 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
>  	int type;
>  
>  	/* Initialize the work for modeset in case of link train failure */
> -	INIT_WORK(&intel_connector->modeset_retry_work,
> +	INIT_WORK(&intel_dp->modeset_retry_work,
>  		  intel_dp_modeset_retry_work_fn);
>  
>  	if (WARN(intel_dig_port->max_lanes < 1,
> diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c
> index f59b59bb0a21..2cfa58ce1f95 100644
> --- a/drivers/gpu/drm/i915/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c
> @@ -340,7 +340,7 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
>  							     intel_dp->link_rate,
>  							     intel_dp->lane_count))
>  			/* Schedule a Hotplug Uevent to userspace to start modeset */
> -			schedule_work(&intel_connector->modeset_retry_work);
> +			schedule_work(&intel_dp->modeset_retry_work);
>  	} else {
>  		DRM_ERROR("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d",
>  			  intel_connector->base.base.id,
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 5bd2263407b2..742d53495974 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -406,9 +406,6 @@ struct intel_connector {
>  
>  	struct intel_dp *mst_port;
>  
> -	/* Work struct to schedule a uevent on link train failure */
> -	struct work_struct modeset_retry_work;
> -
>  	const struct intel_hdcp_shim *hdcp_shim;
>  	struct mutex hdcp_mutex;
>  	uint64_t hdcp_value; /* protected by hdcp_mutex */
> @@ -1143,6 +1140,9 @@ struct intel_dp {
>  
>  	/* Displayport compliance testing */
>  	struct intel_dp_compliance compliance;
> +
> +	/* Work struct to schedule a uevent on link train failure */
> +	struct work_struct modeset_retry_work;
>  };
>  
>  struct intel_lspcon {