diff options
author | Dave Airlie <airlied@redhat.com> | 2014-01-20 10:21:54 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2014-01-20 10:21:54 +1000 |
commit | cfd72a4c2089aa3938f37281a34d6eb3306d5fd8 (patch) | |
tree | e63f6df423aeb59d1ea5f7af3597d6718e75c335 /drivers/tty/tty_ldsem.c | |
parent | 9354eafd893f45320a37da360e1728104e49cc2f (diff) | |
parent | 0d9d349d8788d30f3fc3bb39279c370f94d9dbec (diff) |
Merge branch 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
drm-intel-next-2014-01-10:
- final bits for runtime D3 on Haswell from Paul (now enabled fully)
- parse the backlight modulation freq information in the VBT from Jani
(but not yet used)
- more watermark improvements from Ville for ilk-ivb and bdw
- bugfixes for fastboot from Jesse
- watermark fix for i830M (but not yet everything)
- vlv vga hotplug w/a (Imre)
- piles of other small improvements, cleanups and fixes all over
Note that the pull request includes a backmerge of the last drm-fixes
pulled into Linus' tree - things where getting a bit too messy. So the
shortlog also contains a bunch of patches from Linus tree. Please yell if
you want me to frob it for you a bit.
* 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel: (609 commits)
drm/i915/bdw: make sure south port interrupts are enabled properly v2
drm/i915: Include more information in disabled hotplug interrupt warning
drm/i915: Only complain about a rogue hotplug IRQ after disabling
drm/i915: Only WARN about a stuck hotplug irq ONCE
drm/i915: s/hotplugt_status_gen4/hotplug_status_g4x/
Diffstat (limited to 'drivers/tty/tty_ldsem.c')
-rw-r--r-- | drivers/tty/tty_ldsem.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c index 22fad8ad5ac2..d8a55e87877f 100644 --- a/drivers/tty/tty_ldsem.c +++ b/drivers/tty/tty_ldsem.c @@ -86,11 +86,21 @@ static inline long ldsem_atomic_update(long delta, struct ld_semaphore *sem) return atomic_long_add_return(delta, (atomic_long_t *)&sem->count); } +/* + * ldsem_cmpxchg() updates @*old with the last-known sem->count value. + * Returns 1 if count was successfully changed; @*old will have @new value. + * Returns 0 if count was not changed; @*old will have most recent sem->count + */ static inline int ldsem_cmpxchg(long *old, long new, struct ld_semaphore *sem) { - long tmp = *old; - *old = atomic_long_cmpxchg(&sem->count, *old, new); - return *old == tmp; + long tmp = atomic_long_cmpxchg(&sem->count, *old, new); + if (tmp == *old) { + *old = new; + return 1; + } else { + *old = tmp; + return 0; + } } /* |