Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1610724

[PATCH 4.9 86/88] drm: reference count event->completion

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.9 86/88] drm: reference count event->completion
Date 2017-03-28 14:50 +0200
Message-ID <tpYJu-7Cs-59@gated-at.bofh.it> (permalink)
References <tpYJs-7Cs-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniel Vetter <daniel.vetter@ffwll.ch>

commit 24835e442f289813aa568d142a755672a740503c upstream.

When writing the generic nonblocking commit code I assumed that
through clever lifetime management I can assure that the completion
(stored in drm_crtc_commit) only gets freed after it is completed. And
that worked.

I also wanted to make nonblocking helpers resilient against driver
bugs, by having timeouts everywhere. And that worked too.

Unfortunately taking boths things together results in oopses :( Well,
at least sometimes: What seems to happen is that the drm event hangs
around forever stuck in limbo land. The nonblocking helpers eventually
time out, move on and release it. Now the bug I tested all this
against is drivers that just entirely fail to deliver the vblank
events like they should, and in those cases the event is simply
leaked. But what seems to happen, at least sometimes, on i915 is that
the event is set up correctly, but somohow the vblank fails to fire in
time. Which means the event isn't leaked, it's still there waiting for
eventually a vblank to fire. That tends to happen when re-enabling the
pipe, and then the trap springs and the kernel oopses.

The correct fix here is simply to refcount the crtc commit to make
sure that the event sticks around even for drivers which only
sometimes fail to deliver vblanks for some arbitrary reasons. Since
crtc commits are already refcounted that's easy to do.

References: https://bugs.freedesktop.org/show_bug.cgi?id=96781
Cc: Jim Rees <rees@umich.edu>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161221102331.31033-1-daniel.vetter@ffwll.ch
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/drm_atomic_helper.c |   11 +++++++++++
 drivers/gpu/drm/drm_fops.c          |    2 +-
 include/drm/drmP.h                  |    1 +
 3 files changed, 13 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1382,6 +1382,15 @@ static int stall_checks(struct drm_crtc
 	return ret < 0 ? ret : 0;
 }
 
+void release_crtc_commit(struct completion *completion)
+{
+	struct drm_crtc_commit *commit = container_of(completion,
+						      typeof(*commit),
+						      flip_done);
+
+	drm_crtc_commit_put(commit);
+}
+
 /**
  * drm_atomic_helper_setup_commit - setup possibly nonblocking commit
  * @state: new modeset state to be committed
@@ -1474,6 +1483,8 @@ int drm_atomic_helper_setup_commit(struc
 		}
 
 		crtc_state->event->base.completion = &commit->flip_done;
+		crtc_state->event->base.completion_release = release_crtc_commit;
+		drm_crtc_commit_get(commit);
 	}
 
 	return 0;
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -686,8 +686,8 @@ void drm_send_event_locked(struct drm_de
 	assert_spin_locked(&dev->event_lock);
 
 	if (e->completion) {
-		/* ->completion might disappear as soon as it signalled. */
 		complete_all(e->completion);
+		e->completion_release(e->completion);
 		e->completion = NULL;
 	}
 
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -361,6 +361,7 @@ struct drm_ioctl_desc {
 /* Event queued up for userspace to read */
 struct drm_pending_event {
 	struct completion *completion;
+	void (*completion_release)(struct completion *completion);
 	struct drm_event *event;
 	struct fence *fence;
 	struct list_head link;

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 4.9 00/88] 4.9.19-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 23/88] Input: iforce - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 21/88] Input: elan_i2c - add ASUS EeeBook X205TA special touchpad fw Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 44/88] USB: usbtmc: add missing endpoint sanity check Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 79/88] intel_th: Dont leak module refcount on failure to activate Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 43/88] usb: hub: Fix crash after failure to read BOS descriptor Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 67/88] xen/acpi: upload PM state from init-domain to Xen Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 82/88] libceph: dont set weight to IN when OSD is destroyed Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 22/88] Input: i8042 - add noloop quirk for Dell Embedded Box PC 3000 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 72/88] cpufreq: Restore policy min/max limits on CPU online Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 24/88] Input: ims-pcu - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 01/88] net/openvswitch: Set the ipv6 source tunnel key address attribute correctly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 47/88] uwb: hwa-rc: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 50/88] iio: sw-device: Fix config group initialization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 17/88] socket, bpf: fix sk_filter use after free in sk_clone_lock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 41/88] USB: wusbcore: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 42/88] usb: musb: cppi41: dont check early-TX-interrupt for Isoch transfer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 39/88] USB: lvtest: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 56/88] powerpc/64s: Fix idle wakeup potential to clobber registers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 86/88] drm: reference count event->completion Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 85/88] nl80211: fix dumpit error path RTNL deadlocks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 10/88] net/mlx5e: Use the proper UAPI values when offloading TC vlan actions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 31/88] ALSA: ctxfi: Fix the incorrect check of dma_set_mask() call Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 53/88] parport: fix attempt to write duplicate procfiles Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 32/88] ALSA: hda - Adding a group of pin definition to fix headset problem Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 38/88] USB: uss720: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 28/88] Input: kbtab - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 81/88] Drivers: hv: vmbus: Dont leak memory when a channel is rescinded Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 30/88] ALSA: seq: Fix racy cell insertions during snd_seq_pool_done() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 88/88] crypto: algif_hash - avoid zero-sized array Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 55/88] ext4: lock the xattr block before checksuming it Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 61/88] hwrng: amd - Revert managed API changes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:50 +0200
  [PATCH 4.9 83/88] device-dax: fix pmd/pte fault fallback handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 45/88] USB: usbtmc: fix probe error path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 84/88] drm/bridge: analogix dp: Fix runtime PM state on driver bind Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 62/88] hwrng: geode - Revert managed API changes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 87/88] fbcon: Fix vc attr at deinit Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 66/88] crypto: ccp - Assign DMA commands to the channels CCP Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 48/88] mmc: ushc: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 46/88] uwb: i1480-dfu: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 80/88] Drivers: hv: vmbus: Dont leak channel ids Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:00 +0200
  [PATCH 4.9 08/88] net: vrf: Reset rt6i_idev in local dst after put Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 71/88] arm64: kaslr: Fix up the kernel image alignment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 06/88] net: unix: properly re-increment inflight counter of GC discarded candidates Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 63/88] clk: sunxi-ng: sun6i: Fix enable bit offset for hdmi-ddc module clock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 59/88] mmc: sdhci: Do not disable interrupts while waiting for clock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 51/88] iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 52/88] iio: magnetometer: ak8974: remove incorrect __exit markups Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 05/88] openvswitch: Add missing case OVS_TUNNEL_KEY_ATTR_PAD Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 78/88] jbd2: dont leak memory if setting up journal fails Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 58/88] mmc: sdhci-of-arasan: fix incorrect timeout clock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 54/88] ext4: mark inode dirty after converting inline directory Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 73/88] cgroup, net_cls: iterate the fds of only the tasks which are being migrated Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 74/88] blk-mq: dont complete un-started request in timeout handler Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 40/88] USB: idmouse: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 64/88] clk: sunxi-ng: mp: Adjust parent rate for pre-dividers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 77/88] auxdisplay: img-ascii-lcd: add missing sentinel entry in img_ascii_lcd_matches Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 76/88] drm/amdgpu: reinstate oland workaround for sclk Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 09/88] net/mlx5: Add missing entries for set/query rate limit commands Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 57/88] mmc: sdhci-of-at91: Support external regulators Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 69/88] Revert "ARM: at91/dt: sama5d2: Use new compatible for ohci node" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 65/88] mwifiex: pcie: dont leak DMA buffers when removing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 68/88] iommu/vt-d: Fix NULL pointer dereference in device_to_iommu Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 37/88] usb-core: Add LINEAR_FRAME_INTR_BINTERVAL USB quirk Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 70/88] ARM: at91: pm: cpu_idle: switch DDR to power-down mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 49/88] iio: adc: ti_am335x_adc: fix fifo overrun recovery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
  [PATCH 4.9 75/88] libceph: force GFP_NOIO for socket allocations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:10 +0200
    Re: [PATCH 4.9 75/88] libceph: force GFP_NOIO for socket allocations Michal Hocko <mhocko@kernel.org> - 2017-03-29 10:20 +0200
  [PATCH 4.9 14/88] ipv6: make sure to initialize sockc.tsflags before first use Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 16/88] ipv4: provide stronger user input validation in nl_fib_input() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 02/88] net: bcmgenet: Do not suspend PHY if Wake-on-LAN is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 25/88] Input: hanwang - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 15/88] net: bcmgenet: remove bcmgenet_internal_phy_setup() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 04/88] amd-xgbe: Fix jumbo MTU processing on newer hardware Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 36/88] usb: gadget: f_uvc: Fix SuperSpeed companion descriptors wBytesPerInterval Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 29/88] Input: sur40 - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 03/88] net: properly release sk_frag.page Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 26/88] Input: yealink - validate number of endpoints before using them Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 12/88] net/mlx5e: Count GSO packets correctly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 13/88] net/mlx5e: Count LRO packets correctly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 33/88] USB: serial: option: add Quectel UC15, UC20, EC21, and EC25 modems Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 20/88] Input: ALPS - fix trackstick button handling on V8 devices Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 18/88] tcp: initialize icsk_ack.lrcvtime at session start time Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 19/88] Input: ALPS - fix V8+ protocol handling (73 03 28) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  [PATCH 4.9 11/88] net/mlx5: Increase number of max QPs in default profile Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 15:20 +0200
  Re: [PATCH 4.9 00/88] 4.9.19-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-03-28 21:50 +0200
  Re: [PATCH 4.9 00/88] 4.9.19-stable review Guenter Roeck <linux@roeck-us.net> - 2017-03-29 06:50 +0200
  Re: [PATCH 4.9 00/88] 4.9.19-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-29 07:50 +0200

csiph-web