gpio: sysfs: fix redundant lock-as-irq handling (52176d0d) · Commits · 戴 / test

Drivers should call gpiochip_lock_as_irq (which prevents the pin direction from being changed) in their irq_request_resources callbacks but some drivers currently fail to do so. Instead a second, explicit and often redundant call to lock-as-irq is made by the sysfs-interface implementation after an irq has been requested. Move the explicit call before the irq-request to match the unlock done after the irq is later released. Note that this also fixes an irq leak, should the explicit call ever have failed. Also add a comment about removing the redundant call once the broken drivers have been fixed. Signed-off-by:

Johan Hovold <johan@kernel.org> Reviewed-by:

Alexandre Courbot <acourbot@nvidia.com> Signed-off-by:

Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-sysfs.c

+15 −7

Original line number	Diff line number	Diff line
		@@ -195,20 +195,28 @@ static int gpio_setup_irq(struct gpio_desc desc, struct device dev,
		}
		}

		ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
		"gpiolib", value_sd);
		/*
		* FIXME: This should be done in the irq_request_resources callback
		* when the irq is requested, but a few drivers currently fail
		* to do so.
		*
		* Remove this redundant call (along with the corresponding
		* unlock) when those drivers have been fixed.
		*/
		ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
		if (ret < 0)
		goto free_id;

		ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
		if (ret < 0) {
		gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
		goto free_id;
		}
		ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
		"gpiolib", value_sd);
		if (ret < 0)
		goto err_unlock;

		desc->flags \|= gpio_flags;
		return 0;

		err_unlock:
		gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
		free_id:
		idr_remove(&dirent_idr, id);
		desc->flags &= GPIO_FLAGS_MASK;

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