Re: [PATCH 1/2] i2c: consider devices with of_match_table during i2c device probing
From: Sergey Senozhatsky <hidden>
Date: 2020-08-26 05:07:18
Also in:
linux-acpi, lkml
Subsystem:
i2c subsystem, the rest · Maintainers:
Andi Shyti, Linus Torvalds
On (20/08/26 13:29), Sergey Senozhatsky wrote:
Unlike acpi_match_device(), acpi_driver_match_device() does
consider devices that provide of_match_table and performs
of_compatible() matching for such devices. The key point here is
that ACPI of_compatible() matching - acpi_of_match_device() - is
part of ACPI and does not depend on CONFIG_OF.
Consider the following case:
o !CONFIG_OF system
o probing of i2c device that provides .of_match_table, but no .id_table
i2c_device_probe()
...
if (!driver->id_table &&
!i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
!i2c_of_match_device(dev->driver->of_match_table, client)) {
status = -ENODEV;
goto put_sync_adapter;
}
i2c_of_match_device() depends on CONFIG_OF and, thus, is always false.
i2c_acpi_match_device() does ACPI match only, no of_comtatible() matching
takes place, even though the device provides .of_match_table and ACPI,
technically, is capable of matching such device. The result is -ENODEV.
Probing will succeed, however, if we'd use .of_match_table aware ACPI
matching.Or, alternatively, we can drop i2c_acpi_match_device() and use i2c_device_match() in i2c_device_probe(). ---
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 34a9609f256d..14bfc5c83f84 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c@@ -96,7 +96,6 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; - /* Attempt an OF style match */ if (i2c_of_match_device(drv->of_match_table, client)) return 1;
@@ -480,8 +479,7 @@ static int i2c_device_probe(struct device *dev) * or ACPI ID table is supplied for the probing device. */ if (!driver->id_table && - !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && - !i2c_of_match_device(dev->driver->of_match_table, client)) { + !(client && i2c_device_match(&client->dev, dev->driver))) { status = -ENODEV; goto put_sync_adapter; }
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 94ff1693b391..8ce261167a2d 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h@@ -59,20 +59,11 @@ static inline int __i2c_check_suspended(struct i2c_adapter *adap) } #ifdef CONFIG_ACPI -const struct acpi_device_id * -i2c_acpi_match_device(const struct acpi_device_id *matches, - struct i2c_client *client); void i2c_acpi_register_devices(struct i2c_adapter *adap); int i2c_acpi_get_irq(struct i2c_client *client); #else /* CONFIG_ACPI */ static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { } -static inline const struct acpi_device_id * -i2c_acpi_match_device(const struct acpi_device_id *matches, - struct i2c_client *client) -{ - return NULL; -} static inline int i2c_acpi_get_irq(struct i2c_client *client) {