i2c: core: Allow drivers to disable i2c-core irq mapping (d1d84bb9) · Commits · 戴 / test

By default the i2c-core will try to get an irq with index 0 on ACPI / of instantiated devices. This is troublesome on some ACPI systems where the irq info at index 0 in the CRS table may contain nonsense and/or point to an irqchip for which there is no Linux driver. If this happens then before this commit the driver's probe method would never get called because i2c_device_probe will try to get an irq by calling acpi_dev_gpio_irq_get which will always return -EPROBE in this case, as it waits for a matching irqchip driver to load. Thus causing the driver to not get a chance to bind. This commit adds a new disable_i2c_core_irq_mapping flag to struct i2c_driver which a driver can set to tell the core to skip irq mapping. Signed-off-by:

Hans de Goede <hdegoede@redhat.com> Reviewed-by:

Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:

Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/i2c-core.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -985,7 +985,9 @@ static int i2c_device_probe(struct device *dev)
		if (!client)
		return 0;

		if (!client->irq) {
		driver = to_i2c_driver(dev->driver);

		if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
		int irq = -ENOENT;

		if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
		@@ -1007,8 +1009,6 @@ static int i2c_device_probe(struct device *dev)
		client->irq = irq;
		}

		driver = to_i2c_driver(dev->driver);

		/*
		* An I2C ID table is not mandatory, if and only if, a suitable Device
		* Tree match table entry is supplied for the probing device.

include/linux/i2c.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -149,6 +149,7 @@ enum i2c_alert_protocol {
		* @detect: Callback for device detection
		* @address_list: The I2C addresses to probe (for detect)
		* @clients: List of detected clients we created (for i2c-core use only)
		* @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
		*
		* The driver.owner field should be set to the module owner of this driver.
		* The driver.name field should be set to the name of this driver.
		@@ -212,6 +213,8 @@ struct i2c_driver {
		int (detect)(struct i2c_client , struct i2c_board_info *);
		const unsigned short *address_list;
		struct list_head clients;

		bool disable_i2c_core_irq_mapping;
		};
		#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)

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