drm/amdgpu: Poll for both connect/disconnect on analog connectors
authorLyude <cpaul@redhat.com>
Fri, 24 Jun 2016 21:54:32 +0000 (17:54 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 20 Aug 2016 16:09:22 +0000 (18:09 +0200)
commit2c10a2c5cef3f3ae7dd7cd931398014c2b4c290f
treef8a6c961764f9e9e9f931c34092f057305254c90
parent8f811d101bd2b1c606b5ee1c3a8bd59a4f48cb8d
drm/amdgpu: Poll for both connect/disconnect on analog connectors

commit b636a1b3d624b49b23cc1be2f9f6bcbb89aca855 upstream.

DRM_CONNECTOR_POLL_CONNECT only enables polling for connections, not
disconnections. Because of this, we end up losing hotplug polling for
analog connectors once they get connected.

Easy way to reproduce:
 - Grab a machine with an AMD GPU and a VGA port
 - Plug a monitor into the VGA port, wait for it to update the connector
   from disconnected to connected
 - Disconnect the monitor on VGA, a hotplug event is never sent for the
   removal of the connector.

Originally, only using DRM_CONNECTOR_POLL_CONNECT might have been a good
idea since doing VGA polling can sometimes result in having to mess with
the DAC voltages to figure out whether or not there's actually something
there since VGA doesn't have HPD. Doing this would have the potential of
showing visible artifacts on the screen every time we ran a poll while a
VGA display was connected. Luckily, amdgpu_vga_detect() only resorts to
this sort of polling if the poll is forced, and DRM's polling helper
doesn't force it's polls.

Additionally, this removes some assignments to connector->polled that
weren't actually doing anything.

Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c