powerpc/mpic: supply a .disable callback

Currently MPIC provides .mask, but not .disable.  This means that
effectively disable_irq() soft-disables the interrupt, and you get
a .mask call if an interrupt actually occurs.

I'm not sure if this was intended as a performance benefit (it seems common
to omit .disable on powerpc interrupt controllers, but nowhere else), but it
interacts badly with threaded/workqueue interrupts (including KVM
reflection).  In such cases, where the real interrupt handler does a
disable_irq_nosync(), schedules defered handling, and returns, we get two
interrupts for every real interrupt.  The second interrupt does nothing
but see that IRQ_DISABLED is set, and decide that it would be a good
idea to actually call .mask.

In the sleep case, disable all irqs of IP blocks using .disable()
when entering sleep.

Change-Id: I8f57e20a87acae115d0a8a006d31ffdedb42c295
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao@freescale.com>
Reviewed-on: http://git.am.freescale.net:8181/10507
Reviewed-by: Yang Li <LeoLi@freescale.com>
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Dongsheng Wang <dongsheng.wang@freescale.com>
Reviewed-by: Jose Rivera <German.Rivera@freescale.com>

0 files changed, 0 insertions, 0 deletions