---
name: "drm_kms_helper_poll_init"
section: "9"
platform: "linux"
package: "linux-manual-3.16"
version: "3.16.56-1+deb8u1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/drm_kms_helper_poll_init"
---

# drm\_kms\_helper\_poll\_init(9)

initialize and enable output polling

## NAME

drm\_kms\_helper\_poll\_init - initialize and enable output polling

## SYNOPSIS

**void drm\_kms\_helper\_poll\_init(struct drm\_device \*** *dev***);**

## ARGUMENTS

*dev*

drm\_device

## DESCRIPTION

This function intializes and then also enables output polling support for *dev*. Drivers which do not have reliable hotplug support in hardware can use this helper infrastructure to regularly poll such connectors for changes in their connection state.

Drivers can control which connectors are polled by setting the DRM\_CONNECTOR\_POLL\_CONNECT and DRM\_CONNECTOR\_POLL\_DISCONNECT flags. On connectors where probing live outputs can result in visual distortion drivers should not set the DRM\_CONNECTOR\_POLL\_DISCONNECT flag to avoid this. Connectors which have no flag or only DRM\_CONNECTOR\_POLL\_HPD set are completely ignored by the polling logic.

Note that a connector can be both polled and probed from the hotplug handler, in case the hotplug interrupt is known to be unreliable.

## AUTHORS

**Jesse Barnes** \<jesse.barnes@intel.com\>\
 Intel Corporation,

Initial version

**Laurent Pinchart** \<laurent.pinchart@ideasonboard.com\>\
 Ideas on board SPRL,

Driver internals

**Daniel Vetter** \<daniel.vetter@ffwll.ch\>\
 Intel Corporation,

Contributions all over the place

## COPYRIGHT