[PATCH v2 2/4] drm/i915/dp: Disable unnecessary HPD polling for eDP

[Cavitt, Jonathan]

-----Original Message-----
From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Imre Deak
Sent: Wednesday, October 9, 2024 12:44 PM
To: intel-xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org
Subject: [PATCH v2 2/4] drm/i915/dp: Disable unnecessary HPD polling for eDP
> 
> A registered eDP connector is considered to be always connected, so it's
> unnecessary to poll it for a connect/disconnect event. Polling it
> involves AUX accesses toggling the panel power, which in turn can
> generate a spurious short HPD pulse and possibly a new poll cycle via
> the short HPD handler runtime resuming the device. Avoid this by
> disabling the polling for eDP connectors.
> 
> This avoids IGT tests timing out while waiting for the device to runtime
> suspend, the timeout caused by the above runtime resume->poll->suspend->
> resume cycle keeping the device in the resumed state.
> 
> Testcase: igt/kms_pm_rpm/unverisal-planes
> Signed-off-by: Imre Deak <imre.deak at intel.com>

LGTM.

Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 3eff35dd59b8a..6b27fabd61c37 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -6476,7 +6476,8 @@ intel_dp_init_connector(struct intel_digital_port *dig_port,
>  	if (!HAS_GMCH(dev_priv) && DISPLAY_VER(dev_priv) < 12)
>  		connector->interlace_allowed = true;
>  
> -	intel_connector->polled = DRM_CONNECTOR_POLL_HPD;
> +	if (type != DRM_MODE_CONNECTOR_eDP)
> +		intel_connector->polled = DRM_CONNECTOR_POLL_HPD;
>  	intel_connector->base.polled = intel_connector->polled;
>  
>  	intel_connector_attach_encoder(intel_connector, intel_encoder);
> -- 
> 2.44.2
> 
>