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-rw-r--r--kernel/time/tick-oneshot.c52
1 files changed, 40 insertions, 12 deletions
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 0a8a213016f..aada0e52680 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -22,6 +22,29 @@
22 22
23#include "tick-internal.h" 23#include "tick-internal.h"
24 24
25/* Limit min_delta to a jiffie */
26#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ)
27
28static int tick_increase_min_delta(struct clock_event_device *dev)
29{
30 /* Nothing to do if we already reached the limit */
31 if (dev->min_delta_ns >= MIN_DELTA_LIMIT)
32 return -ETIME;
33
34 if (dev->min_delta_ns < 5000)
35 dev->min_delta_ns = 5000;
36 else
37 dev->min_delta_ns += dev->min_delta_ns >> 1;
38
39 if (dev->min_delta_ns > MIN_DELTA_LIMIT)
40 dev->min_delta_ns = MIN_DELTA_LIMIT;
41
42 printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
43 dev->name ? dev->name : "?",
44 (unsigned long long) dev->min_delta_ns);
45 return 0;
46}
47
25/** 48/**
26 * tick_program_event internal worker function 49 * tick_program_event internal worker function
27 */ 50 */
@@ -37,23 +60,28 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
37 if (!ret || !force) 60 if (!ret || !force)
38 return ret; 61 return ret;
39 62
63 dev->retries++;
40 /* 64 /*
41 * We tried 2 times to program the device with the given 65 * We tried 3 times to program the device with the given
42 * min_delta_ns. If that's not working then we double it 66 * min_delta_ns. If that's not working then we increase it
43 * and emit a warning. 67 * and emit a warning.
44 */ 68 */
45 if (++i > 2) { 69 if (++i > 2) {
46 /* Increase the min. delta and try again */ 70 /* Increase the min. delta and try again */
47 if (!dev->min_delta_ns) 71 if (tick_increase_min_delta(dev)) {
48 dev->min_delta_ns = 5000; 72 /*
49 else 73 * Get out of the loop if min_delta_ns
50 dev->min_delta_ns += dev->min_delta_ns >> 1; 74 * hit the limit already. That's
51 75 * better than staying here forever.
52 printk(KERN_WARNING 76 *
53 "CE: %s increasing min_delta_ns to %llu nsec\n", 77 * We clear next_event so we have a
54 dev->name ? dev->name : "?", 78 * chance that the box survives.
55 (unsigned long long) dev->min_delta_ns << 1); 79 */
56 80 printk(KERN_WARNING
81 "CE: Reprogramming failure. Giving up\n");
82 dev->next_event.tv64 = KTIME_MAX;
83 return -ETIME;
84 }
57 i = 0; 85 i = 0;
58 } 86 }
59 87