From: Sven Schnelle <svens@linux.ibm.com>
Date: Thu, 10 Jul 2025 07:43:40 +0000 (+0200)
Subject: s390/sclp: Use monotonic clock in sclp_sync_wait()
X-Git-Tag: v6.16.2~349
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cad8c5b7d137c1f8be6203d70c1ac870fcd3afc6;p=thirdparty%2Fkernel%2Fstable.git

s390/sclp: Use monotonic clock in sclp_sync_wait()

[ Upstream commit 925f0707a67cae0a974c4bd5b718f0263dc56824 ]

sclp_sync_wait() should use the monotonic clock for the delay loop.
Otherwise the code won't work correctly when the clock is changed.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 840be75e75d41..9a55e2d04e633 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -719,7 +719,7 @@ sclp_sync_wait(void)
 	timeout = 0;
 	if (timer_pending(&sclp_request_timer)) {
 		/* Get timeout TOD value */
-		timeout = get_tod_clock_fast() +
+		timeout = get_tod_clock_monotonic() +
 			  sclp_tod_from_jiffies(sclp_request_timer.expires -
 						jiffies);
 	}
@@ -739,7 +739,7 @@ sclp_sync_wait(void)
 	/* Loop until driver state indicates finished request */
 	while (sclp_running_state != sclp_running_state_idle) {
 		/* Check for expired request timer */
-		if (get_tod_clock_fast() > timeout && timer_delete(&sclp_request_timer))
+		if (get_tod_clock_monotonic() > timeout && timer_delete(&sclp_request_timer))
 			sclp_request_timer.function(&sclp_request_timer);
 		cpu_relax();
 	}