thinkpad-acpi: untangle ACPI/vendor backlight selection
acpi_video_backlight_support() already tells us if ACPI is handling
backlight control through the generic ACPI handle. It is better to just
trust it.
While at it, adjust down a printk priority, and test earlier for
brightness_enable=0.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index f6f8025..1565eef 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -1024,6 +1024,10 @@
backlight brightness control interface if it detects that the standard
ACPI interface is available in the ThinkPad.
+If you want to use the thinkpad-acpi backlight brightness control
+instead of the generic ACPI video backlight brightness control for some
+reason, you should use the acpi_backlight=vendor kernel parameter.
+
The brightness_enable module parameter can be used to control whether
the LCD brightness control feature will be enabled when available.
brightness_enable=0 forces it to be disabled. brightness_enable=1
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 9d6fc4c..b9430e8 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6216,28 +6216,6 @@
if (tp_features.bright_unkfw)
return 1;
- if (tp_features.bright_acpimode) {
- if (acpi_video_backlight_support()) {
- if (brightness_enable > 1) {
- printk(TPACPI_NOTICE
- "Standard ACPI backlight interface "
- "available, not loading native one.\n");
- return 1;
- } else if (brightness_enable == 1) {
- printk(TPACPI_NOTICE
- "Backlight control force enabled, even if standard "
- "ACPI backlight interface is available\n");
- }
- } else {
- if (brightness_enable > 1) {
- printk(TPACPI_NOTICE
- "Standard ACPI backlight interface not "
- "available, thinkpad_acpi native "
- "brightness control enabled\n");
- }
- }
- }
-
if (!brightness_enable) {
dbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT,
"brightness support disabled by "
@@ -6245,6 +6223,26 @@
return 1;
}
+ if (acpi_video_backlight_support()) {
+ if (brightness_enable > 1) {
+ printk(TPACPI_INFO
+ "Standard ACPI backlight interface "
+ "available, not loading native one.\n");
+ return 1;
+ } else if (brightness_enable == 1) {
+ printk(TPACPI_WARN
+ "Cannot enable backlight brightness support, "
+ "ACPI is already handling it. Refer to the "
+ "acpi_backlight kernel parameter\n");
+ return 1;
+ }
+ } else if (tp_features.bright_acpimode && brightness_enable > 1) {
+ printk(TPACPI_NOTICE
+ "Standard ACPI backlight interface not "
+ "available, thinkpad_acpi native "
+ "brightness control enabled\n");
+ }
+
/*
* Check for module parameter bogosity, note that we
* init brightness_mode to TPACPI_BRGHT_MODE_MAX in order to be