diff mbox series

[04/24] timekeeping: Abort clocksource change in case of failure

Message ID 20240911-devel-anna-maria-b4-timers-ptp-timekeeping-v1-4-f7cae09e25d6@linutronix.de (mailing list archive)
State Not Applicable
Headers show
Series timekeeping: Rework to prepare support of indenpendent PTP clocks | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Anna-Maria Behnsen Sept. 11, 2024, 1:29 p.m. UTC
From: Thomas Gleixner <tglx@linutronix.de>

There is no point to go through a full timekeeping update when acquiring a
module reference or enabling the new clocksource fails.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
---
 kernel/time/timekeeping.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)
diff mbox series

Patch

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index bdc4a6fe040d..7b80dd70062c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1577,33 +1577,29 @@  static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
 static int change_clocksource(void *data)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	struct clocksource *new, *old = NULL;
+	struct clocksource *new = data, *old = NULL;
 	unsigned long flags;
-	bool change = false;
-
-	new = (struct clocksource *) data;
 
 	/*
-	 * If the cs is in module, get a module reference. Succeeds
-	 * for built-in code (owner == NULL) as well.
+	 * If the clocksource is in a module, get a module reference.
+	 * Succeeds for built-in code (owner == NULL) as well. Abort if the
+	 * reference can't be acquired.
 	 */
-	if (try_module_get(new->owner)) {
-		if (!new->enable || new->enable(new) == 0)
-			change = true;
-		else
-			module_put(new->owner);
+	if (!try_module_get(new->owner))
+		return 0;
+
+	/* Abort if the device can't be enabled */
+	if (new->enable && new->enable(new) != 0) {
+		module_put(new->owner);
+		return 0;
 	}
 
 	raw_spin_lock_irqsave(&timekeeper_lock, flags);
 	write_seqcount_begin(&tk_core.seq);
 
 	timekeeping_forward_now(tk);
-
-	if (change) {
-		old = tk->tkr_mono.clock;
-		tk_setup_internals(tk, new);
-	}
-
+	old = tk->tkr_mono.clock;
+	tk_setup_internals(tk, new);
 	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
 
 	write_seqcount_end(&tk_core.seq);
@@ -1612,7 +1608,6 @@  static int change_clocksource(void *data)
 	if (old) {
 		if (old->disable)
 			old->disable(old);
-
 		module_put(old->owner);
 	}