diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 0c048dd8013f65..d3b0b4fba4d97b 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -62,6 +62,14 @@ struct hv_device_info { struct hv_dev_port_info outbound; }; +static int vmbus_exists(void) +{ + if (hv_acpi_dev == NULL) + return -ENODEV; + + return 0; +} + static void get_channel_info(struct hv_device *device, struct hv_device_info *info) @@ -590,6 +598,10 @@ int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, c pr_info("registering driver %s\n", hv_driver->name); + ret = vmbus_exists(); + if (ret < 0) + return ret; + hv_driver->driver.name = hv_driver->name; hv_driver->driver.owner = owner; hv_driver->driver.mod_name = mod_name; @@ -614,6 +626,9 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver) { pr_info("unregistering driver %s\n", hv_driver->name); + if (!vmbus_exists()) + return; + driver_unregister(&hv_driver->driver); } @@ -776,6 +791,7 @@ static int __init hv_acpi_init(void) cleanup: acpi_bus_unregister_driver(&vmbus_acpi_driver); + hv_acpi_dev = NULL; return ret; }