Patch "drm/amdgpu: Don't link train DisplayPort on HPD until we get the dpcd" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/amdgpu: Don't link train DisplayPort on HPD until we get the dpcd

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-amdgpu-don-t-link-train-displayport-on-hpd-until-we-get-the-dpcd.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a887adadb7b9ef9eb4ee48e4ad575aefcfd1db14 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Fri, 21 Aug 2015 18:07:38 -0400
Subject: drm/amdgpu: Don't link train DisplayPort on HPD until we get the dpcd

From: Alex Deucher <alexander.deucher@amd.com>

commit a887adadb7b9ef9eb4ee48e4ad575aefcfd1db14 upstream.

This is a port of:
DRM - radeon: Don't link train DisplayPort on HPD until we get the dpcd
to amdgpu.

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 |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
@@ -75,6 +75,11 @@ void amdgpu_connector_hotplug(struct drm
 			if (!amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd)) {
 				drm_helper_connector_dpms(connector, DRM_MODE_DPMS_OFF);
 			} else if (amdgpu_atombios_dp_needs_link_train(amdgpu_connector)) {
+				/* Don't try to start link training before we
+				 * have the dpcd */
+				if (!amdgpu_atombios_dp_get_dpcd(amdgpu_connector))
+					return;
+
 				/* set it to OFF so that drm_helper_connector_dpms()
 				 * won't return immediately since the current state
 				 * is ON at this point.


Patches currently in stable-queue which might be from alexander.deucher@amd.com are

queue-4.2/drm-amdgpu-atom-send-out-the-full-aux-address.patch
queue-4.2/drm-radeon-atom-send-out-the-full-aux-address.patch
queue-4.2/drm-amdgpu-fix-ih-ring-allocation-for-bus-addresses-v2.patch
queue-4.2/drm-radeon-don-t-link-train-displayport-on-hpd-until-we-get-the-dpcd.patch
queue-4.2/drm-amdgpu-fix-typo-in-dce11-watermark-setup.patch
queue-4.2/drm-radeon-native-send-out-the-full-aux-address.patch
queue-4.2/drm-amdgpu-don-t-link-train-displayport-on-hpd-until-we-get-the-dpcd.patch
queue-4.2/drm-radeon-fix-hdmi-quantization_range-for-pre-dce5-asics.patch
queue-4.2/drm-amdgpu-fix-typo-in-dce10-watermark-setup.patch