Commit bad4da12 authored Oct 31, 2018 by Brian Masney Committed by Greg Kroah-Hartman Dec 01, 2019

pinctrl: qcom: spmi-gpio: fix gpio-hog related boot issues



[ Upstream commit 149a96047237574b756d872007c006acd0cc6687 ]

When attempting to setup up a gpio hog, device probing would repeatedly
fail with -EPROBE_DEFERED errors. It was caused by a circular dependency
between the gpio and pinctrl frameworks. If the gpio-ranges property is
present in device tree, then the gpio framework will handle the gpio pin
registration and eliminate the circular dependency.

See Christian Lamparter's commit a86caa9b ("pinctrl: msm: fix
gpio-hog related boot issues") for a detailed commit message that
explains the issue in much more detail. The code comment in this commit
came from Christian's commit.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent c24fe780

drivers/pinctrl/qcom/pinctrl-spmi-gpio.c

+17 −4

Original line number	Diff line number	Diff line
		@@ -1028,11 +1028,24 @@ static int pmic_gpio_probe(struct platform_device *pdev)
		return ret;
		}

		ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0, npins);
		/*
		* For DeviceTree-supported systems, the gpio core checks the
		* pinctrl's device node for the "gpio-ranges" property.
		* If it is present, it takes care of adding the pin ranges
		* for the driver. In this case the driver can skip ahead.
		*
		* In order to remain compatible with older, existing DeviceTree
		* files which don't set the "gpio-ranges" property or systems that
		* utilize ACPI the driver has to call gpiochip_add_pin_range().
		*/
		if (!of_property_read_bool(dev->of_node, "gpio-ranges")) {
		ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0,
		npins);
		if (ret) {
		dev_err(dev, "failed to add pin range\n");
		goto err_range;
		}
		}

		return 0;