Daniel Vetter c75fe78995 drm: reference count event->completion ... commit 24835e442f 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>		2017-03-30 09:41:28 +02:00
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acpi	ACPICA: Linuxize: Restore and fix Intel compiler build	2017-02-26 11:10:52 +01:00
asm-generic	asm-prototypes: Clear any CPP defines before declaring the functions	2017-01-12 11:39:07 +01:00
clocksource
crypto	crypto: drbg - prevent invalid SG mappings	2016-11-30 19:46:44 +08:00
drm	drm: reference count event->completion	2017-03-30 09:41:28 +02:00
dt-bindings	ARM: dts: r8a7794: remove Z clock	2017-01-26 08:24:36 +01:00
keys
kvm
linux	crypto: ccp - Assign DMA commands to the channel's CCP	2017-03-30 09:41:26 +02:00
math-emu
media
memory
misc
net	tcp: don't annotate mark on control socket from tcp_v6_send_response()	2017-02-18 15:11:44 +01:00
pcmcia
ras
rdma	RDMA/core: Fix incorrect structure packing for booleans	2017-03-12 06:41:50 +01:00
rxrpc
scsi	scsi: libiscsi: add lock around task lists to fix list corruption regression	2017-03-26 13:05:58 +02:00
soc	ARM: at91: define LPDDR types	2017-03-12 06:41:41 +01:00
sound	ASoC: hdmi-codec: use unsigned type to structure members with bit-field	2017-01-19 20:18:02 +01:00
target	target: Fix NULL dereference during LUN lookup + active I/O shutdown	2017-03-15 10:02:46 +08:00
trace	tracing: Add #undef to fix compile error	2017-03-18 19:14:29 +08:00
uapi	uapi: fix linux/packet_diag.h userspace compilation error	2017-03-22 12:43:34 +01:00
video
xen
Kbuild