[tip:x86/timers] x86/time: Unconditionally register legacy timer interrupt

tip-bot for Peter Zijlstra
2018-01-14T19:24:39Z

Commit-ID: 6d671e1b85c63e7a337ba76c1a154c091545cff8
Gitweb: https://git.kernel.org/tip/6d671e1b85c63e7a337ba76c1a154c091545cff8
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Fri, 22 Dec 2017 10:20:12 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 14 Jan 2018 20:18:23 +0100

x86/time: Unconditionally register legacy timer interrupt

Even without a PIC/PIT the legacy timer interrupt is required for HPET in
legacy replacement mode.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.382623763@infradead.org

---
arch/x86/kernel/time.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
index 749d189..774ebaf 100644
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -69,9 +69,12 @@ static struct irqaction irq0 = {

static void __init setup_default_timer_irq(void)
{
- if (!nr_legacy_irqs())
- return;
- setup_irq(0, &irq0);
+ /*
+ * Unconditionally register the legacy timer; even without legacy
+ * PIC/PIT we need this for the HPET0 in legacy replacement mode.
+ */
+ if (setup_irq(0, &irq0))
+ pr_info("Failed to register legacy timer interrupt\n");
}

/* Default timer init function */