xtensa: clear timer IRQ unconditionally in its handler

PIC irq_ack doesn't clear timer IRQ, because timer interrupt handler
usually set up new timer by writing to ccompare register and thus
clearing timer IRQ. However timer may not be set up in the IRQ handler,
e.g. with tickless idle on SMP, or when CPU is going offline, leaving
timer IRQ raised and making do_interrupt attempting to handle it
forever.

To fix this always write current value of ccompare SR chosen to be linux
timer back to that SR on entry to timer interrupt handler.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 4ce7aae39e64342ef40761d051cfddf6ee284c6b..60dcb3fcaeae8ad978f8eeec4d073a88abb9f064 100644 (file)
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -158,6 +158,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
 {
        struct clock_event_device *evt = &this_cpu_ptr(&ccount_timer)->evt;
 
+       set_linux_timer(get_linux_timer());
        evt->event_handler(evt);
 
        /* Allow platform to do something useful (Wdog). */