[PATCH] mmp: irq: Don't clear unused interrupt enable bits

[Daniel Drake]

On Thu, Jun 27, 2013 at 11:15 PM, Eric Miao <eric.y.miao at gmail.com> wrote:
> Is there any way to check this at run-time or at least by boot parameters?

The only thing that occurs to me would be checking for the device tree
node that corresponds to our input serio. But doing that from platform
code would be horrible, and it would also be nasty doing it from the
input driver.

> Decide whether the interrupt gets delivered to SP seems to be a choice
> that the main CPU should be doing, as well as the interrupt priority.

Incidentally the main CPU does make these choices - just before Linux
has booted.

While Linux has no interaction with the SP (it is not even aware of
it), I would say not stomping on its configuration is an OK policy to
have.

> And this is really all about bit 4 right?

Yes, bit 4 is the crucial one, it is required for the OLPC inbuilt
keyboard/touchpad to work.

However on numerous occasions during interactions with Marvell they
have stressed the importance of setting interrupt priorities on
interrupts used for wakeups. We don't think it makes a difference for
the issues that we have seen, but we do not ignore the request. As
that cannot be done in Linux, we do it in the firmware, and it seems
like while Linux does not work with interrupt priorities it should not
overwite any earlier setup.

Daniel