[PATCH] platform/x86: thinkpad_acpi: not loading brightness_init when _BCL invalid

From: Aaron Ma
Date: Thu Jul 02 2020 - 04:55:44 EST


When _BCL invalid, disable thinkpad_acpi backlight brightness control.

brightness_enable is already checked at the beginning,
Always print notice when enabled brightness control.

Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
---
drivers/platform/x86/thinkpad_acpi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index ff7f0a4f2475..a52d6d457d6c 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6955,10 +6955,13 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
pr_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) {
- pr_notice("Standard ACPI backlight interface not available, thinkpad_acpi native brightness control enabled\n");
+ } else if (!tp_features.bright_acpimode) {
+ pr_notice("thinkpad_acpi backlight interface not available\n");
+ return 1;
}

+ pr_notice("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
--
2.26.2