Re: [PATCH v3 Update] drm/i915: Add bit field to record which pins have received HPD events (v3)

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

On Thu, 11 Apr 2013, Egbert Eich <eich@suse.de> wrote:
> This allows to add code which limits 're'-detect() of displays to connectors
> that have received an HPD event.
>
> v2: Reordered drm_i915_private: Move hpd_event_bits to hpd state tracking.
> v3: Fixed merge conflicts with previous patches, removed some noisy debug
>     logging as suggested by Jani Nikula.

Okay, I'm not generally enthusiastic about adding #if 0 stuff. If we're
going to remove that later anyway, we might just as well add the noisy
debug print and remove *that* later. I'll just dodge this and let Daniel
decide. Both versions get my

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


>
> Signed-off-by: Egbert Eich <eich@suse.de>
> ---
> (Sorry for the spam, I had accidenty went the wrong version of this patch)
>
>  drivers/gpu/drm/i915/i915_drv.h |  1 +
>  drivers/gpu/drm/i915/i915_irq.c | 12 ++++++++++++
>  2 files changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 195b9fe..c0d9fb9 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -938,6 +938,7 @@ typedef struct drm_i915_private {
>  			HPD_MARK_DISABLED = 2
>  		} hpd_mark;
>  	} hpd_stats[HPD_NUM_PINS];
> +	u32 hpd_event_bits;
>  	struct timer_list hotplug_reenable_timer;
>  
>  	int num_pch_pll;
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index f60c643..6e643d7 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -350,6 +350,7 @@ static void i915_hotplug_work_func(struct work_struct *work)
>  	struct drm_connector *connector;
>  	unsigned long irqflags;
>  	bool hpd_disabled = false;
> +	u32 hpd_event_bits;
>  
>  	/* HPD irq before everything is fully set up. */
>  	if (!dev_priv->enable_hotplug_processing)
> @@ -359,6 +360,9 @@ static void i915_hotplug_work_func(struct work_struct *work)
>  	DRM_DEBUG_KMS("running encoder hotplug functions\n");
>  
>  	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> +
> +	hpd_event_bits = dev_priv->hpd_event_bits;
> +	dev_priv->hpd_event_bits = 0;
>  	list_for_each_entry(connector, &mode_config->connector_list, head) {
>  		intel_connector = to_intel_connector(connector);
>  		intel_encoder = intel_connector->encoder;
> @@ -373,6 +377,12 @@ static void i915_hotplug_work_func(struct work_struct *work)
>  				| DRM_CONNECTOR_POLL_DISCONNECT;
>  			hpd_disabled = true;
>  		}
> +#if 0
> +		if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
> +			DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n",
> +				      drm_get_connector_name(connector), intel_encoder->hpd_pin);
> +		}
> +#endif
>  	}
>  	 /* if there were no outputs to poll, poll was disabled,
>  	  * therefore make sure it's enabled when disabling HPD on
> @@ -632,6 +642,7 @@ static inline bool hotplug_irq_storm_detect(struct drm_device *dev,
>  	for (i = 1; i < HPD_NUM_PINS; i++) {
>  		if ((hpd[i] & hotplug_trigger) &&
>  		    dev_priv->hpd_stats[i].hpd_mark == HPD_ENABLED) {
> +			dev_priv->hpd_event_bits |= (1 << i);
>  			if (!time_in_range(jiffies, dev_priv->hpd_stats[i].hpd_last_jiffies,
>  					  dev_priv->hpd_stats[i].hpd_last_jiffies
>  					  + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) {
> @@ -639,6 +650,7 @@ static inline bool hotplug_irq_storm_detect(struct drm_device *dev,
>  				dev_priv->hpd_stats[i].hpd_cnt = 0;
>  			} else if (dev_priv->hpd_stats[i].hpd_cnt > 5) {
>  				dev_priv->hpd_stats[i].hpd_mark = HPD_MARK_DISABLED;
> +				dev_priv->hpd_event_bits &= ~(1 << i);
>  				DRM_DEBUG_KMS("HPD interrupt storm detected on  PIN %d\n", i);
>  				ret = true;
>  			} else
> -- 
> 1.8.1.4