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@xxxxxxxxxx>
---
Changes in v2:
-Actually also use the irq_index for of interrupts
Changes in v3:
-Add kernel doc for new i2c_driver irq_index member
-Remove duplicate assignment of driver in i2c_device_probe
Changes in v4:
-Add a disable_i2c_core_irq_mapping flag to i2c_driver instead of
an irq_index member (effectively a rewrite of the patch, dropped
the Reviewed-by-s)
---
drivers/i2c/i2c-core.c | 6 +++---
include/linux/i2c.h | 3 +++
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 00c4cef..7a065c4 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -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.
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 53fa50f..3a57e3d 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -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)
--
2.9.3
--
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