Patch "drm/fb_helper: Disable all crtc's when initial setup fails." has been added to the 4.14-stable tree

Patch "drm/fb_helper: Disable all crtc's when initial setup fails." has been added to the 4.14-stable tree

[gregkh]

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

    drm/fb_helper: Disable all crtc's when initial setup fails.

to the 4.14-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-fb_helper-disable-all-crtc-s-when-initial-setup-fails.patch
and it can be found in the queue-4.14 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 52dd06506e9bbc2a37b352df7dfc5468f8da21fd Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Tue, 28 Nov 2017 12:16:03 +0100
Subject: drm/fb_helper: Disable all crtc's when initial setup fails.

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

commit 52dd06506e9bbc2a37b352df7dfc5468f8da21fd upstream.

Some drivers like i915 start with crtc's enabled, but with deferred
fbcon setup they were no longer disabled as part of fbdev setup.
Headless units could no longer enter pc3 state because the crtc was
still enabled.

Fix this by calling restore_fbdev_mode when we would have called
it otherwise once during initial fbdev setup.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: ca91a2758fce ("drm/fb-helper: Support deferred setup")
Reported-by: Thomas Voegtle <tv@lio96.de>
Tested-by: Thomas Voegtle <tv@lio96.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171128111603.62757-1-maarten.lankhorst@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/drm_fb_helper.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1809,6 +1809,10 @@ static int drm_fb_helper_single_fb_probe
 
 	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
 		DRM_INFO("Cannot find any crtc or sizes\n");
+
+		/* First time: disable all crtc's.. */
+		if (!fb_helper->deferred_setup && !READ_ONCE(fb_helper->dev->master))
+			restore_fbdev_mode(fb_helper);
 		return -EAGAIN;
 	}
 


Patches currently in stable-queue which might be from maarten.lankhorst@linux.intel.com are

queue-4.14/drm-fb_helper-disable-all-crtc-s-when-initial-setup-fails.patch