From 83ac7a1c2ed5f17caa07cbbc84bad3c05dc3bf22 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Thu, 25 Aug 2022 16:13:34 +0200
Subject: [PATCH] platform/x86: msi-laptop: Fix old-ec check for backlight registering
Git-commit: 83ac7a1c2ed5f17caa07cbbc84bad3c05dc3bf22
Patch-mainline: v6.1-rc1
References: git-fixes

Commit 2cc6c717799f ("msi-laptop: Port to new backlight interface
selection API") replaced this check:

	if (!quirks->old_ec_model || acpi_video_backlight_support())
		pr_info("Brightness ignored, ...");
	else
		do_register();

With: 

	if (quirks->old_ec_model ||
	    acpi_video_get_backlight_type() == acpi_backlight_vendor)
		do_register();

But since the do_register() part was part of the else branch, the entire
condition should be inverted.  So not only the 2 statements on either
side of the || should be inverted, but the || itself should be replaced
with a &&.

In practice this has likely not been an issue because the new-ec models
(old_ec_model==false) likely all support ACPI video backlight control,
making acpi_video_get_backlight_type() return acpi_backlight_video
turning the second part of the || also false when old_ec_model == false.

Fixes: 2cc6c717799f ("msi-laptop: Port to new backlight interface selection API")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220825141336.208597-1-hdegoede@redhat.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/platform/x86/msi-laptop.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/platform/x86/msi-laptop.c b/drivers/platform/x86/msi-laptop.c
index 93ef8851b93e..54170172a666 100644
--- a/drivers/platform/x86/msi-laptop.c
+++ b/drivers/platform/x86/msi-laptop.c
@@ -1047,8 +1047,7 @@ static int __init msi_init(void)
 		return -EINVAL;
 
 	/* Register backlight stuff */
-
-	if (quirks->old_ec_model ||
+	if (quirks->old_ec_model &&
 	    acpi_video_get_backlight_type() == acpi_backlight_vendor) {
 		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
-- 
2.35.3