i2c: Not all adapters have a parent

The code in acpi_i2c_register_devices() assumes that all i2c adapters
have a parent. This is not necessarily the case, for example the
i2c-stub driver instantiate a virtual i2c adapter without a parent.
Check for this to avoid a NULL pointer deference.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 29d3f045a2bf..3be58f89ac77 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1134,6 +1134,9 @@ static void acpi_i2c_register_devices(struct i2c_adapter *adap)
         acpi_handle handle;
         acpi_status status;
 
+        if (!adap->dev.parent)
+                return;
+
         handle = ACPI_HANDLE(adap->dev.parent);
         if (!handle)
                 return;