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authorDavid Woodhouse <David.Woodhouse@intel.com>2012-10-09 15:03:21 +0100
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-10-09 15:04:25 +0100
commitffe315012510165ce82e4dd4767f0a5dba9edbf7 (patch)
treef601cd980af9d0ced5ca9aedecef4fa0d2ca0e15 /lib/spinlock_debug.c
parente2d3a35ee427aaba99b6c68a56609ce276c51270 (diff)
parent4a8e43feeac7996b8de2d5b2823e316917493df4 (diff)
Merge tag 'disintegrate-mtd-20121009' of git://git.infradead.org/users/dhowells/linux-headers
UAPI Disintegration 2012-10-09 Conflicts: MAINTAINERS arch/arm/configs/bcmring_defconfig arch/arm/mach-imx/clk-imx51-imx53.c drivers/mtd/nand/Kconfig drivers/mtd/nand/bcm_umi_nand.c drivers/mtd/nand/nand_bcm_umi.h drivers/mtd/nand/orion_nand.c
Diffstat (limited to 'lib/spinlock_debug.c')
-rw-r--r--lib/spinlock_debug.c32
1 files changed, 18 insertions, 14 deletions
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index eb10578ae05..0374a596cff 100644
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -107,23 +107,27 @@ static void __spin_lock_debug(raw_spinlock_t *lock)
{
u64 i;
u64 loops = loops_per_jiffy * HZ;
- int print_once = 1;
- for (;;) {
- for (i = 0; i < loops; i++) {
- if (arch_spin_trylock(&lock->raw_lock))
- return;
- __delay(1);
- }
- /* lockup suspected: */
- if (print_once) {
- print_once = 0;
- spin_dump(lock, "lockup suspected");
+ for (i = 0; i < loops; i++) {
+ if (arch_spin_trylock(&lock->raw_lock))
+ return;
+ __delay(1);
+ }
+ /* lockup suspected: */
+ spin_dump(lock, "lockup suspected");
#ifdef CONFIG_SMP
- trigger_all_cpu_backtrace();
+ trigger_all_cpu_backtrace();
#endif
- }
- }
+
+ /*
+ * The trylock above was causing a livelock. Give the lower level arch
+ * specific lock code a chance to acquire the lock. We have already
+ * printed a warning/backtrace at this point. The non-debug arch
+ * specific code might actually succeed in acquiring the lock. If it is
+ * not successful, the end-result is the same - there is no forward
+ * progress.
+ */
+ arch_spin_lock(&lock->raw_lock);
}
void do_raw_spin_lock(raw_spinlock_t *lock)