summaryrefslogtreecommitdiff
path: root/kernel/time/clocksource.c
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2024-02-01 21:40:42 +0300
committerTakashi Iwai <tiwai@suse.de>2024-02-01 21:40:42 +0300
commitd4ea2bd1bb502c54380cc44a4130660494679bb8 (patch)
tree7d14962a86c24026ce2eee8f9e67db610db23fd8 /kernel/time/clocksource.c
parenteaa1b01fe709d6a236a9cec74813e0400601fd23 (diff)
parente81fdba0208666b65bafeaba814874b4d6e5edde (diff)
downloadlinux-d4ea2bd1bb502c54380cc44a4130660494679bb8.tar.xz
Merge tag 'asoc-fix-v6.8-rc2-2' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v6.8 This pull request adds Richard Fitzgerald's series with extensive fixes for the CS35L56, he said: These patches fix various things that were undocumented, unknown or uncertain when the original driver code was written. And also a few things that were just bugs.
Diffstat (limited to 'kernel/time/clocksource.c')
-rw-r--r--kernel/time/clocksource.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c108ed8a9804..3052b1f1168e 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -99,6 +99,7 @@ static u64 suspend_start;
* Interval: 0.5sec.
*/
#define WATCHDOG_INTERVAL (HZ >> 1)
+#define WATCHDOG_INTERVAL_MAX_NS ((2 * WATCHDOG_INTERVAL) * (NSEC_PER_SEC / HZ))
/*
* Threshold: 0.0312s, when doubled: 0.0625s.
@@ -134,6 +135,7 @@ static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
static DEFINE_SPINLOCK(watchdog_lock);
static int watchdog_running;
static atomic_t watchdog_reset_pending;
+static int64_t watchdog_max_interval;
static inline void clocksource_watchdog_lock(unsigned long *flags)
{
@@ -399,8 +401,8 @@ static inline void clocksource_reset_watchdog(void)
static void clocksource_watchdog(struct timer_list *unused)
{
u64 csnow, wdnow, cslast, wdlast, delta;
+ int64_t wd_nsec, cs_nsec, interval;
int next_cpu, reset_pending;
- int64_t wd_nsec, cs_nsec;
struct clocksource *cs;
enum wd_read_status read_ret;
unsigned long extra_wait = 0;
@@ -470,6 +472,27 @@ static void clocksource_watchdog(struct timer_list *unused)
if (atomic_read(&watchdog_reset_pending))
continue;
+ /*
+ * The processing of timer softirqs can get delayed (usually
+ * on account of ksoftirqd not getting to run in a timely
+ * manner), which causes the watchdog interval to stretch.
+ * Skew detection may fail for longer watchdog intervals
+ * on account of fixed margins being used.
+ * Some clocksources, e.g. acpi_pm, cannot tolerate
+ * watchdog intervals longer than a few seconds.
+ */
+ interval = max(cs_nsec, wd_nsec);
+ if (unlikely(interval > WATCHDOG_INTERVAL_MAX_NS)) {
+ if (system_state > SYSTEM_SCHEDULING &&
+ interval > 2 * watchdog_max_interval) {
+ watchdog_max_interval = interval;
+ pr_warn("Long readout interval, skipping watchdog check: cs_nsec: %lld wd_nsec: %lld\n",
+ cs_nsec, wd_nsec);
+ }
+ watchdog_timer.expires = jiffies;
+ continue;
+ }
+
/* Check the deviation from the watchdog clocksource. */
md = cs->uncertainty_margin + watchdog->uncertainty_margin;
if (abs(cs_nsec - wd_nsec) > md) {