Add patches to fix qxl locking issues (rhbz 1238803 1249850)

3 files changed, 102 insertions, 0 deletions

diff --git a/drm-qxl-avoid-buffer-reservation-in-qxl_crtc_page_fl.patch b/drm-qxl-avoid-buffer-reservation-in-qxl_crtc_page_fl.patch
new file mode 100644
index 000000000..34a8b7973
--- /dev/null
+++ b/drm-qxl-avoid-buffer-reservation-in-qxl_crtc_page_fl.patch
@@ -0,0 +1,53 @@
+From fc6c6a4dde53bf68c519c0079b5957a24b7bad2b Mon Sep 17 00:00:00 2001
+From: Frediano Ziglio <fziglio@redhat.com>
+Date: Thu, 24 Sep 2015 14:25:14 +0100
+Subject: [PATCH 1/2] drm/qxl: avoid buffer reservation in qxl_crtc_page_flip
+
+This avoid a dependency lock error.
+According to https://lwn.net/Articles/548909/ users of WW mutex API
+should avoid using different context.
+When a buffer is reserved with qxl_bo_reserve a ww_mutex_lock without
+context is used. However during qxl_draw_dirty_fb different locks
+with specific context are used.
+This is detected during a machine booting with a debug kernel with lock
+dependency checking enabled.
+Like many other function in this file to avoid this problem object
+pinning is used. Once the object is pinned is not necessary to keep
+the lock so it can be released avoiding the locking problem.
+
+Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
+---
+ drivers/gpu/drm/qxl/qxl_display.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
+index 4649bd2ed340..183aea1abebc 100644
+--- a/drivers/gpu/drm/qxl/qxl_display.c
++++ b/drivers/gpu/drm/qxl/qxl_display.c
+@@ -244,6 +244,10 @@ static int qxl_crtc_page_flip(struct drm_crtc *crtc,
+ 	ret = qxl_bo_reserve(bo, false);
+ 	if (ret)
+ 		return ret;
++	ret = qxl_bo_pin(bo, bo->type, NULL);
++	qxl_bo_unreserve(bo);
++	if (ret)
++		return ret;
+ 
+ 	qxl_draw_dirty_fb(qdev, qfb_src, bo, 0, 0,
+ 			  &norect, one_clip_rect, inc);
+@@ -257,7 +261,11 @@ static int qxl_crtc_page_flip(struct drm_crtc *crtc,
+ 	}
+ 	drm_vblank_put(dev, qcrtc->index);
+ 
+-	qxl_bo_unreserve(bo);
++	ret = qxl_bo_reserve(bo, false);
++	if (!ret) {
++		qxl_bo_unpin(bo);
++		qxl_bo_unreserve(bo);
++	}
+ 
+ 	return 0;
+ }
+-- 
+2.4.3
+
diff --git a/drm-qxl-avoid-dependency-lock.patch b/drm-qxl-avoid-dependency-lock.patch
new file mode 100644
index 000000000..27aea6957
--- /dev/null
+++ b/drm-qxl-avoid-dependency-lock.patch
@@ -0,0 +1,42 @@
+From 364222966c6cb48898b83f9a912bff4cedcda2cd Mon Sep 17 00:00:00 2001
+From: Frediano Ziglio <fziglio@redhat.com>
+Date: Thu, 24 Sep 2015 14:25:15 +0100
+Subject: [PATCH 2/2] drm/qxl: avoid dependency lock
+
+qxl_bo_unref calls drm_gem_object_unreference_unlocked which
+locks dev->struct_mutex. However this lock could be already
+locked if the call came from qxl_gem_object_free.
+As we don't need to call qxl_bo_ref/qxl_bo_unref cause
+qxl_release_list_add will hold a reference by itself avoid
+to call them and the possible deadlock.
+
+Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
+---
+ drivers/gpu/drm/qxl/qxl_release.c | 4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
+index b66ec331c17c..4efa8e261baf 100644
+--- a/drivers/gpu/drm/qxl/qxl_release.c
++++ b/drivers/gpu/drm/qxl/qxl_release.c
+@@ -307,7 +307,7 @@ int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
+ 		idr_ret = qxl_release_alloc(qdev, QXL_RELEASE_SURFACE_CMD, release);
+ 		if (idr_ret < 0)
+ 			return idr_ret;
+-		bo = qxl_bo_ref(to_qxl_bo(entry->tv.bo));
++		bo = to_qxl_bo(entry->tv.bo);
+ 
+ 		(*release)->release_offset = create_rel->release_offset + 64;
+ 
+@@ -316,8 +316,6 @@ int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
+ 		info = qxl_release_map(qdev, *release);
+ 		info->id = idr_ret;
+ 		qxl_release_unmap(qdev, *release, info);
+-
+-		qxl_bo_unref(&bo);
+ 		return 0;
+ 	}
+ 
+-- 
+2.4.3
+
diff --git a/kernel.spec b/kernel.spec
index 87fbe6c4f..84a338c39 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -592,6 +592,10 @@ Patch520: ARM-dts-Fix-Makefile-target-for-sun4i-a10-itead-itea.patch
 #rhbz 1262434
 Patch521: Revert-Input-synaptics-fix-handling-of-disabling-ges.patch
 
+#rhbz 1238803 1249850
+Patch522: drm-qxl-avoid-buffer-reservation-in-qxl_crtc_page_fl.patch
+Patch523: drm-qxl-avoid-dependency-lock.patch
+
 Patch904: kdbus.patch
 
 # END OF PATCH DEFINITIONS
@@ -2037,6 +2041,9 @@ fi
 #
 # 
 %changelog
+* Mon Oct 05 2015 Josh Boyer <jwboyer@fedoraproject.org>
+- Add patches to fix qxl locking issues (rhbz 1238803 1249850)
+
 * Sun Oct  4 2015 Peter Robinson <pbrobinson@fedoraproject.org>
 - Add support for BeagleBone Green