On Mon, 2017-06-26 at 15:32 +0300, Paul Kocialkowski wrote:
> After detecting an IRQ storm, hotplug detection will switch from
> irq-based detection to poll-based detection. After a short delay or
> when resetting storm detection from debugfs, detection will switch
> back to being irq-based.
>
> However, it may occur that polling does not have enough time to detect
> the current connector state when that second switch takes place.
Some questions so that I understand this better. How short would this
have to be for detect to not complete? Is there a way I can easily test
this scenario?
> Thus,
> this sets the appropriate hotplug event bits for the concerned
> connectors and schedules the hotplug work, that will ensure the
> connectors states are in sync when switching back to irq.
>
Not sure I understand this correctly, looks like you are setting the
event_bits even if there was no irq during the polling interval. Is that
right?
> Without this, no irq will be triggered and the hpd change will be lost.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkow...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/intel_hotplug.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_hotplug.c
> b/drivers/gpu/drm/i915/intel_hotplug.c
> index f1200272a699..29f55480b0bb 100644
> --- a/drivers/gpu/drm/i915/intel_hotplug.c
> +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> @@ -218,9 +218,13 @@ static void intel_hpd_irq_storm_reenable_work(struct
> work_struct *work)
> struct intel_connector *intel_connector =
> to_intel_connector(connector);
>
> if (intel_connector->encoder->hpd_pin == i) {
> - if (connector->polled !=
> intel_connector->polled)
> + if (connector->polled !=
> intel_connector->polled) {
> DRM_DEBUG_DRIVER("Reenabling HPD on
> connector %s\n",
> connector->name);
> +
> + dev_priv->hotplug.event_bits |= (1 <<
> i);
> + }
> +
> connector->polled = intel_connector->polled;
> if (!connector->polled)
> connector->polled =
> DRM_CONNECTOR_POLL_HPD;
> @@ -232,6 +236,8 @@ static void intel_hpd_irq_storm_reenable_work(struct
> work_struct *work)
> dev_priv->display.hpd_irq_setup(dev_priv);
> spin_unlock_irq(&dev_priv->irq_lock);
>
> + schedule_work(&dev_priv->hotplug.hotplug_work);
How does this work with DP connectors? From what I understand, the
event_bits are set for DP based on the return value from
intel_dp_hpd_pulse(). But, doesn't this patch set the bits
unconditionally?
> +
> intel_runtime_pm_put(dev_priv);
> }
>
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