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

We currently defer probing of the caller if a pinctrl GPIO
request or direction setting comes in before the range mapping
a certain GPIO to a certain pin controller is available.

This can end up with a circular dependency: the GPIO driver
needs the pin controller to be ready and the pin controller
need the GPIO driver to be ready. This also happens if
pin controllers and GPIO controllers compiled as modules
are inserted in a certain order.

To break this circular dependence, queue any GPIO
operations coming to the framework until the range is ready,
instead of deferring the probe of the caller.

I just noticed that next-20130819 is failing on the Tegra114 Dalmore
board because of this patch. The kernel log is below. Reverting this
patch solves the problem

[   12.427751] tegra114-pinctrl 70000868.pinmux: pin USB_VBUS_EN0 PN4 already requested by Tegra GPIOs:108; cannot claim for Tegra GPIOs:108
[   12.440320] tegra114-pinctrl 70000868.pinmux: pin-108 (Tegra GPIOs:108) status -22
[   12.447965] usb1_vbus: Failed to request enable GPIO108: -22
[   12.454306] reg-fixed-voltage 3.regulator: Failed to register regulator: -22
[   12.461508] reg-fixed-voltage: probe of 3.regulator failed with error -22
[   12.469659] tegra114-pinctrl 70000868.pinmux: pin SPDIF_IN PK6 already requested by Tegra GPIOs:86; cannot claim for Tegra GPIOs:86
[   12.481606] tegra114-pinctrl 70000868.pinmux: pin-86 (Tegra GPIOs:86) status -22
[   12.489052] usb2_vbus: Failed to request enable GPIO86: -22
[   12.495226] reg-fixed-voltage 4.regulator: Failed to register regulator: -22
[   12.502449] reg-fixed-voltage: probe of 4.regulator failed with error -22
[   12.510542] tegra114-pinctrl 70000868.pinmux: pin GMI_CLK PK1 already requested by Tegra GPIOs:81; cannot claim for Tegra GPIOs:81
[   12.522403] tegra114-pinctrl 70000868.pinmux: pin-81 (Tegra GPIOs:81) status -22
[   12.529896] vdd_hdmi_5v0: Failed to request enable GPIO81: -22
[   12.536281] reg-fixed-voltage 5.regulator: Failed to register regulator: -22
[   12.543465] reg-fixed-voltage: probe of 5.regulator failed with error -22
[   12.552509] vdd_cam_1v8_reg: 1800 mV 
[   12.558205] platform 7d008000.usb: Driver tegra-ehci requests probe deferral
[   12.566600] platform 7d008000.usb-phy: Driver tegra-phy requests probe deferral
[   12.577475] input: gpio-keys.2 as /devices/soc0/gpio-keys.2/input/input1
[   12.588329] platform 7d008000.usb: Driver tegra-ehci requests probe deferral
[   12.596967] platform 7d008000.usb-phy: Driver tegra-phy requests probe deferral