[4.2.y-ckt stable] Patch "Revert "drm/radeon: call hpd_irq_event on resume"" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    Revert "drm/radeon: call hpd_irq_event on resume"

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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>From 5e0fcbffeb2a2bf153b91e7e5f76f0c13d961df0 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds at linux-foundation.org>
Date: Mon, 7 Mar 2016 13:15:09 -0800
Subject: Revert "drm/radeon: call hpd_irq_event on resume"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 256faedcfd646161477d47a1a78c32a562d2e845 upstream.

This reverts commit dbb17a21c131eca94eb31136eee9a7fe5aff00d9.

It turns out that commit can cause problems for systems with multiple
GPUs, and causes X to hang on at least a HP Pavilion dv7 with hybrid
graphics.

This got noticed originally in 4.4.4, where this patch had already
gotten back-ported, but 4.5-rc7 was verified to have the same problem.

Alexander Deucher says:
 "It looks like you have a muxed system so I suspect what's happening is
  that one of the display is being reported as connected for both the
  IGP and the dGPU and then the desktop environment gets confused or
  there some sort problem in the detect functions since the mux is not
  switched to the dGPU.  I don't see an easy fix unless Dave has any
  ideas.  I'd say just revert for now"

Reported-by: Jörg-Volker Peetz <jvpeetz at web.de>
Acked-by: Alexander Deucher <Alexander.Deucher at amd.com>
Cc: Dave Airlie <airlied at gmail.com>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/radeon/radeon_device.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index fa98309..d8319da 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1740,7 +1740,6 @@ int radeon_resume_kms(struct drm_device *dev, bool resume, bool fbcon)
 	}

 	drm_kms_helper_poll_enable(dev);
-	drm_helper_hpd_irq_event(dev);

 	/* set the power state here in case we are a PX system or headless */
 	if ((rdev->pm.pm_method == PM_METHOD_DPM) && rdev->pm.dpm_enabled)
--
2.7.0