Hi,
On 20-11-18 16:59, Andy Shevchenko wrote:
i2c_acpi_new_device() doesn't assign fwnode like it's done, for example,
in i2c_acpi_register_devices() path.
Assign fwnode in i2c_acpi_new_device() as it's done elsewhere.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
As already mentioned in my reply to the cover letter, a NACK from me for
this one.
The problem is that this causes the fwnode to be shared by all the
"struct device"-s (embedded in the i2c-clients created).
This in itself is not necessarily a problem, but it does become a
problem when combined with using device_add_properties as
intel_cht_int33fe.c does.
Since the info in the ACPI tables for devices which use this
driver is pretty terrible, we add a bunch of properties to notify
the drivers about how the different parts which make up the Type-C
functionality are tied together.
device_add_properties creates a new fwnode and then calls
set_secondary_fwnode. For devices which already have a fwnode
assigned (which the i2c-clients will have after this patch)
set_secondary_fwnode sets dev->fwnode->secondary to the fwnode
which has been newly created to hold the added properties.
Since all i2c-clients instantiated now share dev->fwnode,
the result of this is that all i2c-clients created now will
have the properties of the last i2c-client instantiated for
an acpi-node which describes multiple clients in a single
node.
Also the fwnodes created for the properties of earlier
instantiated i2c-clients will be leaked.
I see 2 possible solutions here:
1) Changing this patch so that i2c_acpi_new_device() does:
/*
* The fwnode can not be shared between instantiated clients when
* adding device-properties to the instantiated client.
*/
if (!info->properties)
info->fwnode = acpi_fwnode_handle(adev);
2) Leave whether info->fwnode should be set or not up to the
caller of i2c_acpi_new_device() (info is already passed in as
a param). E.g. i2c-multi-instantiate.c could do this (for now,
maybe in the future we will also want to add properties for
some HIDs).
I think that 1. is the best solution and this is all kernel internal,
so we can always revisit this if necessary.
Regards,
Hans
---
drivers/i2c/i2c-core-acpi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index af4b5bd5d973..478862abb82a 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -420,6 +420,7 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
if (!adapter)
return NULL;
+ info->fwnode = acpi_fwnode_handle(adev);
return i2c_new_device(adapter, info);
}
EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
