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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-04-23 11:16:56 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-04-24 12:47:34 +0200
commitac1e55b1fdb27c1b07a0a6fe519f1291ff1e7d40 (patch)
tree7183d2191203d8d923f122f4b3a9dc3e60c101ca
parent6d08b06e67cd117f6992c46611dfb4ce267cd71e (diff)
ACPI / button: make module loadable when booted in non-ACPI mode
Modules such as nouveau.ko and i915.ko have a link time dependency on acpi_lid_open(), and due to its use of acpi_bus_register_driver(), the button.ko module that provides it is only loadable when booted in ACPI mode. However, the ACPI button driver can be built into the core kernel as well, in which case the dependency can always be satisfied, and the dependent modules can be loaded regardless of whether the system was booted in ACPI mode or not. So let's fix this asymmetry by making the ACPI button driver loadable as a module even if not booted in ACPI mode, so it can provide the acpi_lid_open() symbol in the same way as when built into the kernel. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [ rjw: Minor adjustments of comments, whitespace and names. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/acpi/button.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index e1eee7a60fad..f1cc4f9d31cd 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -635,4 +635,26 @@ module_param_call(lid_init_state,
NULL, 0644);
MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
-module_acpi_driver(acpi_button_driver);
+static int acpi_button_register_driver(struct acpi_driver *driver)
+{
+ /*
+ * Modules such as nouveau.ko and i915.ko have a link time dependency
+ * on acpi_lid_open(), and would therefore not be loadable on ACPI
+ * capable kernels booted in non-ACPI mode if the return value of
+ * acpi_bus_register_driver() is returned from here with ACPI disabled
+ * when this driver is built as a module.
+ */
+ if (acpi_disabled)
+ return 0;
+
+ return acpi_bus_register_driver(driver);
+}
+
+static void acpi_button_unregister_driver(struct acpi_driver *driver)
+{
+ if (!acpi_disabled)
+ acpi_bus_unregister_driver(driver);
+}
+
+module_driver(acpi_button_driver, acpi_button_register_driver,
+ acpi_button_unregister_driver);