From d34afa9de4447367b734ec407e5a9e10617d6ec3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 30 May 2014 04:27:31 +0200 Subject: [PATCH] ACPI / scan: Change the meaning of missing .attach() in scan handlers Currently, some scan handlers can be compiled out entirely, which leaves the device objects they normally attach to without a scan handler. This isn't a problem as long as we don't have any default enumeration mechanism that applies to all devices without a scan handler. However, if such a default enumeration is added, it still should not be applied to devices that are normally attached to by scan handlers, because that may result in creating "physical" device objects of a wrong type for them. Since we are going to create platform device objects for all ACPI device objects with pnp.type.platform_id set by default, clear pnp.type.platform_id where there is a matching scan handler without an .attach() callback and otherwise simply treat that scan handler as though the .attach() callback was present but always returned 0. This will allow us to compile out scan handler callbacks and leave the device ID lists used by them so as to prevent creating platform device objects for the matching ACPI devices. Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg --- drivers/acpi/scan.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index ebbd23c94ba2..611bb5db7e57 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -84,7 +84,7 @@ EXPORT_SYMBOL_GPL(acpi_initialize_hp_context); int acpi_scan_add_handler(struct acpi_scan_handler *handler) { - if (!handler || !handler->attach) + if (!handler) return -EINVAL; list_add_tail(&handler->list_node, &acpi_scan_handlers_list); @@ -2081,6 +2081,10 @@ static int acpi_scan_attach_handler(struct acpi_device *device) handler = acpi_scan_match_handler(hwid->id, &devid); if (handler) { + if (!handler->attach) { + device->pnp.type.platform_id = 0; + continue; + } device->handler = handler; ret = handler->attach(device, devid); if (ret > 0) -- 2.20.1