On Mon, Aug 19, 2013 at 9:15 PM, Stephen Warren [off-list ref] wrote:

On 08/17/2013 08:56 AM, Linus Walleij wrote:

quoted

and the pin controller need the GPIO driver to be ready.

Why does that happen?

The pin controller call back into the GPIO-side controller
functions by utilizing the GPIO ranges.
(Maybe the code is silly, I dunno, check drivers/pinctrl/pinctrl-nomadik.c)

quoted

This also happens if
pin controllers and GPIO controllers compiled as modules
are inserted in a certain order.

Shouldn't deferred probe resolve that just fine, assuming there are no
circular dependencies?

The above leads to circular dependencies so that is what I'm
trying to fix with this.

quoted

On the Nomadik we get this situation with the pinctrl
driver when moving to requesting GPIOs off the gpiochip
right after it has been added,

So, the pinctrl driver calls gpio_request()? Surely the solution is
simply not to do that?

This is what the other patch we're discussing is doing.
The one that harvests and requests interrupt GPIO's when
a gpiochip is added...

Yours,
Linus Walleij