ASoc: simple-mux: Allow to specify an idle-state

Merge series from "Hendrik v. Raven" <h.v.raven@merzmedtech.de>:

This series adds support for the idle-state property from the mux
framework to the simple-mux audio variant. It allows to specify the state
of the mux when it is not in use.

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 6513c53c9459..c5fb28e6451a 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -440,7 +440,19 @@ static int lapic_timer_shutdown(struct clock_event_device *evt)
 	v = apic_read(APIC_LVTT);
 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
 	apic_write(APIC_LVTT, v);
-	apic_write(APIC_TMICT, 0);
+
+	/*
+	 * Setting APIC_LVT_MASKED (above) should be enough to tell
+	 * the hardware that this timer will never fire. But AMD
+	 * erratum 411 and some Intel CPU behavior circa 2024 say
+	 * otherwise.  Time for belt and suspenders programming: mask
+	 * the timer _and_ zero the counter registers:
+	 */
+	if (v & APIC_LVT_TIMER_TSCDEADLINE)
+		wrmsrl(MSR_IA32_TSC_DEADLINE, 0);
+	else
+		apic_write(APIC_TMICT, 0);
+
 	return 0;
 }