[PATCH 2/3] x86/time: Unconditionally register legacy timer interrupt

Peter Zijlstra
2017-12-22T09:24:14Z

[-- Attachment #1: peterz-uncondition-legacy-timer.patch --]
[-- Type: text/plain, Size: 786 bytes --]

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

Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/time.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- 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 */