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-rw-r--r--kernel/hrtimer.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index d55092ceee29..6b715c0af1b1 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -234,6 +234,11 @@ again:
234 goto again; 234 goto again;
235 } 235 }
236 timer->base = new_base; 236 timer->base = new_base;
237 } else {
238 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
239 cpu = this_cpu;
240 goto again;
241 }
237 } 242 }
238 return new_base; 243 return new_base;
239} 244}
@@ -569,6 +574,23 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
569 574
570 cpu_base->expires_next.tv64 = expires_next.tv64; 575 cpu_base->expires_next.tv64 = expires_next.tv64;
571 576
577 /*
578 * If a hang was detected in the last timer interrupt then we
579 * leave the hang delay active in the hardware. We want the
580 * system to make progress. That also prevents the following
581 * scenario:
582 * T1 expires 50ms from now
583 * T2 expires 5s from now
584 *
585 * T1 is removed, so this code is called and would reprogram
586 * the hardware to 5s from now. Any hrtimer_start after that
587 * will not reprogram the hardware due to hang_detected being
588 * set. So we'd effectivly block all timers until the T2 event
589 * fires.
590 */
591 if (cpu_base->hang_detected)
592 return;
593
572 if (cpu_base->expires_next.tv64 != KTIME_MAX) 594 if (cpu_base->expires_next.tv64 != KTIME_MAX)
573 tick_program_event(cpu_base->expires_next, 1); 595 tick_program_event(cpu_base->expires_next, 1);
574} 596}