i2c / ACPI: Do not touch an I2C device if it belongs to another adapter

[cascardo/linux.git] / drivers / i2c / i2c-core.c

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6524266..cdbbd9b 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -168,6 +168,7 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
 
 static int i2c_acpi_get_info(struct acpi_device *adev,
                             struct i2c_board_info *info,
+                            struct i2c_adapter *adapter,
                             acpi_handle *adapter_handle)
 {
        struct list_head resource_list;
@@ -182,8 +183,24 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
        if (ret)
                return ret;
 
+       if (adapter) {
+               /* The adapter must match the one in I2cSerialBus() connector */
+               if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
+                       return -ENODEV;
+       } else {
+               struct acpi_device *adapter_adev;
+
+               /* The adapter must be present */
+               if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
+                       return -ENODEV;
+               if (acpi_bus_get_status(adapter_adev) ||
+                   !adapter_adev->status.present)
+                       return -ENODEV;
+       }
+
        info->fwnode = acpi_fwnode_handle(adev);
-       *adapter_handle = lookup.adapter_handle;
+       if (adapter_handle)
+               *adapter_handle = lookup.adapter_handle;
 
        /* Then fill IRQ number if any */
        INIT_LIST_HEAD(&resource_list);
@@ -225,16 +242,12 @@ static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 {
        struct i2c_adapter *adapter = data;
        struct acpi_device *adev;
-       acpi_handle adapter_handle;
        struct i2c_board_info info;
 
        if (acpi_bus_get_device(handle, &adev))
                return AE_OK;
 
-       if (i2c_acpi_get_info(adev, &info, &adapter_handle))
-               return AE_OK;
-
-       if (adapter_handle != ACPI_HANDLE(&adapter->dev))
+       if (i2c_acpi_get_info(adev, &info, adapter, NULL))
                return AE_OK;
 
        i2c_acpi_register_device(adapter, adev, &info);
@@ -368,7 +381,7 @@ static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 
        switch (value) {
        case ACPI_RECONFIG_DEVICE_ADD:
-               if (i2c_acpi_get_info(adev, &info, &adapter_handle))
+               if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
                        break;
 
                adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);