This is a note to let you know that I've just added the patch titled platform/x86: msi-laptop: Fix old-ec check for backlight registering to the 5.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: platform-x86-msi-laptop-fix-old-ec-check-for-backlig.patch and it can be found in the queue-5.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a5c2546c81fd94afd9e5384eb3d74b7e40e8964a Author: Hans de Goede <hdegoede@xxxxxxxxxx> Date: Thu Aug 25 16:13:34 2022 +0200 platform/x86: msi-laptop: Fix old-ec check for backlight registering [ Upstream commit 83ac7a1c2ed5f17caa07cbbc84bad3c05dc3bf22 ] 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220825141336.208597-1-hdegoede@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/platform/x86/msi-laptop.c b/drivers/platform/x86/msi-laptop.c index 24ffc8e2d2d1..0960205ee49f 100644 --- a/drivers/platform/x86/msi-laptop.c +++ b/drivers/platform/x86/msi-laptop.c @@ -1048,8 +1048,7 @@ 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));