From ae5340cdd6f259cbd3f8e938236b7052c5d209e5 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 7bb1e531325b..1b8652cf0218 100644 --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -192,7 +192,8 @@ 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)