Patch "drm/i915: Avoid stalling on pending flips for legacy cursor updates" has been added to the 4.5-stable tree

Patch "drm/i915: Avoid stalling on pending flips for legacy cursor updates" has been added to the 4.5-stable tree

[gregkh]

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

    drm/i915: Avoid stalling on pending flips for legacy cursor updates

to the 4.5-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-i915-avoid-stalling-on-pending-flips-for-legacy-cursor-updates.patch
and it can be found in the queue-4.5 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 7ac7d19f808697abe6658c64c96868f728273f9c Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sun, 17 Apr 2016 20:42:46 +0100
Subject: drm/i915: Avoid stalling on pending flips for legacy cursor updates
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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From: Chris Wilson <chris@chris-wilson.co.uk>

commit 7ac7d19f808697abe6658c64c96868f728273f9c upstream.

The legacy cursor ioctl expects to be asynchronous with respect to other
screen updates, in particular page flips. As X updates the cursor from a
signal context, if the cursor blocks then it will stall both the input
and output chains causing bad stuttering and horrible UX.

Reported-and-tested-by: Rafael Ristovski <rafael.ristovski@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94980
Fixes: 5008e874edd34 ("drm/i915: Make wait_for_flips interruptible.")
Suggested-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460922166-20292-1-git-send-email-chris@chris-wilson.co.uk
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
(cherry picked from commit acf4e84d6167317ff21be5c03e1ea76ea5783701)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_display.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13429,6 +13429,9 @@ static int intel_atomic_prepare_commit(s
 	}
 
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		if (state->legacy_cursor_update)
+			continue;
+
 		ret = intel_crtc_wait_for_pending_flips(crtc);
 		if (ret)
 			return ret;


Patches currently in stable-queue which might be from chris@chris-wilson.co.uk are

queue-4.5/drm-i915-avoid-stalling-on-pending-flips-for-legacy-cursor-updates.patch