[Xen-devel] [PATCH RFC v2 3/3] x86/hvm/rtc: Always deassert the IRQ line when clearing REG_C.IRQF.

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

From: Tim Deegan <tim@xxxxxxx>

Even in no-ack mode, there's no reason to leave the line asserted
after an explicit ack of the interrupt.

Furthermore, rtc_update_irq() is an unconditional noop having just cleared
RTC_REG_C.

Signed-off-by: Tim Deegan <tim@xxxxxxx>
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/hvm/rtc.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c
index 7a37ebb..1844f2d 100644
--- a/xen/arch/x86/hvm/rtc.c
+++ b/xen/arch/x86/hvm/rtc.c
@@ -678,9 +678,8 @@ static uint32_t rtc_ioport_read(RTCState *s, uint32_t addr)
         check_for_pf_ticks(s);
         ret = s->hw.cmos_data[s->hw.cmos_index];
         s->hw.cmos_data[RTC_REG_C] = 0x00;
-        if ( (ret & RTC_IRQF) && !rtc_mode_is(s, no_ack) )
+        if ( ret & RTC_IRQF )
             hvm_isa_irq_deassert(d, RTC_IRQ);
-        rtc_update_irq(s);
         check_update_timer(s);
         alarm_timer_update(s);
         s->pt_dead_ticks = 0;
-- 
1.7.10.4


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