From 09be4abbfaea64431e8d3b8bb73af73a9ea42a47 Mon Sep 17 00:00:00 2001 From: Nicholas Bishop Date: Fri, 11 Feb 2022 14:57:39 -0500 Subject: [PATCH] drm/radeon: Fix backlight control on iMac 12,1 commit 364438fd629f7611a84c8e6d7de91659300f1502 upstream. The iMac 12,1 does not use the gmux driver for backlight, so the radeon backlight device is needed to set the brightness. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1838 Signed-off-by: Nicholas Bishop Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/radeon/atombios_encoders.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c index e67ed383e11b1..79aef5c063fae 100644 --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -193,7 +193,8 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder, * so don't register a backlight device */ if ((rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) && - (rdev->pdev->device == 0x6741)) + (rdev->pdev->device == 0x6741) && + !dmi_match(DMI_PRODUCT_NAME, "iMac12,1")) return; if (!radeon_encoder->enc_priv)