Chris Wilson 182c594668 dma-buf/fence: Fix lock inversion within dma-fence-array ...

[ Upstream commit 03e4e0a9e0 ]

Ages ago Rob Clark noted,

"Currently with fence-array, we have a potential deadlock situation.  If
we fence_add_callback() on an array-fence, the array-fence's lock is
acquired first, and in it's ->enable_signaling() callback, it will install
cbs on it's array-member fences, so the array-member's lock is acquired
second.

But in the signal path, the array-member's lock is acquired first, and
the array-fence's lock acquired second."

Rob proposed either extensive changes to dma-fence to unnest the
fence-array signaling, or to defer the signaling onto a workqueue. This
is a more refined version of the later, that should keep the latency
of the fence signaling to a minimum by using an irq-work, which is
executed asap.

Reported-by: Rob Clark <robdclark@gmail.com>
Suggested-by: Rob Clark <robdclark@gmail.com>
References: 1476635975-21981-1-git-send-email-robdclark@gmail.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114162719.30958-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2018-03-19 08:42:47 +01:00

..

acpi

ACPI / EC: Fix regression related to PM ops support in ECDT device

2017-12-05 11:26:33 +01:00

asm-generic

init: Invoke init_espfix_bsp() from mm_init()

2017-12-29 17:53:45 +01:00

clocksource

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

crypto

crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t

2018-03-03 10:24:29 +01:00

drm

drm/nouveau: prefer XBGR2101010 for addfb ioctl

2018-03-15 10:54:30 +01:00

dt-bindings

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

keys

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

kvm

arm/arm64: KVM: Turn kvm_psci_version into a static inline

2018-02-16 20:22:55 +01:00

linux

dma-buf/fence: Fix lock inversion within dma-fence-array

2018-03-19 08:42:47 +01:00

math-emu

…

media

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

memory

…

misc

…

net

udplite: fix partial checksum initialization

2018-03-08 22:41:10 -08:00

pcmcia

…

ras

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

rdma

IB/core: Fix ib_wc structure size to remain in 64 bytes boundary

2018-02-22 15:42:14 +01:00

scsi

scsi: core: Avoid that ATA error handling can trigger a kernel hang or oops

2018-03-15 10:54:29 +01:00

soc

Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

2017-09-10 20:40:00 -07:00

sound

ALSA: hda - Fix yet remaining issue with vmaster 0dB initialization

2017-11-30 08:40:49 +00:00

target

target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK

2017-11-30 08:40:51 +00:00

trace

clk: fix a panic error caused by accessing NULL pointer

2018-02-25 11:08:02 +01:00

uapi

uapi libc compat: add fallback for unsupported libcs

2018-03-03 10:24:34 +01:00

video

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

xen

xen/balloon: Mark unallocated host memory as UNUSABLE

2018-03-03 10:24:28 +01:00