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Commit 8f89441b37536fea92b1ed7004e5e2dda011473d

Authored by Thomas Gleixner
Committed by Linus Torvalds
1 parent 3c46bdcaec
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

clocksource: fix lock order in the resume path 

lockdep complains about the lock nesting of clocksource and watchdog lock
in the resume path.

Change the resume marker to a bit operation and remove the lock from this
path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 3 additions and 7 deletions Side-by-side Diff

kernel/time/clocksource.c
Diff comments   View file @ 8f89441
... ... @@ -74,7 +74,7 @@
74 74 static struct timer_list watchdog_timer;
75 75 static DEFINE_SPINLOCK(watchdog_lock);
76 76 static cycle_t watchdog_last;
77   -static int watchdog_resumed;
  77 +static unsigned long watchdog_resumed;
78 78  
79 79 /*
80 80 * Interval: 0.5sec Threshold: 0.0625s
... ... @@ -104,9 +104,7 @@
104 104  
105 105 spin_lock(&watchdog_lock);
106 106  
107   - resumed = watchdog_resumed;
108   - if (unlikely(resumed))
109   - watchdog_resumed = 0;
  107 + resumed = test_and_clear_bit(0, &watchdog_resumed);
110 108  
111 109 wdnow = watchdog->read();
112 110 wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
... ... @@ -151,9 +149,7 @@
151 149 }
152 150 static void clocksource_resume_watchdog(void)
153 151 {
154   - spin_lock(&watchdog_lock);
155   - watchdog_resumed = 1;
156   - spin_unlock(&watchdog_lock);
  152 + set_bit(0, &watchdog_resumed);
157 153 }
158 154  
159 155 static void clocksource_check_watchdog(struct clocksource *cs)