|author||Vineet Gupta <firstname.lastname@example.org>||2015-10-17 15:29:59 +0530|
|committer||Vineet Gupta <email@example.com>||2017-08-28 15:17:36 -0700|
|parent||ARC: [plat-eznps] disabled stall counter due to a HW bug (diff)|
ARC: spinlock: Document the EX based spin_unlock
Signed-off-by: Vineet Gupta <firstname.lastname@example.org>
Diffstat (limited to '')
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
index 233d5ffe6ec7..968c730ef114 100644
@@ -296,6 +296,12 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock)
+ * EX is not really required here, a simple STore of 0 suffices.
+ * However this causes tasklist livelocks in SystemC based SMP virtual
+ * platforms where the systemc core scheduler uses EX as a cue for
+ * moving to next core. Do a git log of this file for details
" ex %0, [%1] \n"
: "+r" (val)