powerpc/4xx/uic: clear pending interrupt after irq type/pol change

When testing out gpio-keys with a button, a spurious
interrupt (and therefore a key press or release event)
gets triggered as soon as the driver enables the irq
line for the first time.

This patch clears any potential bogus generated interrupt
that was caused by the switching of the associated irq's
type and polarity.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/4xx/uic.c b/arch/powerpc/platforms/4xx/uic.c
index 8b4dd0d..9e27cfe 100644 (file)
--- a/arch/powerpc/platforms/4xx/uic.c
+++ b/arch/powerpc/platforms/4xx/uic.c
@@ -158,6 +158,7 @@ static int uic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 
        mtdcr(uic->dcrbase + UIC_PR, pr);
        mtdcr(uic->dcrbase + UIC_TR, tr);
+       mtdcr(uic->dcrbase + UIC_SR, ~mask);
 
        raw_spin_unlock_irqrestore(&uic->lock, flags);