From: Mark Hawrylak <mark.hawrylak@xxxxxxxxx> commit 05eacc198c68cbb35a7281ce4011f8899ee1cfb8 upstream. Apple iMac11,2 (mid 2010) also with Radeon HD-4670 that has the same issue as iMac10,1 (late 2009) where the internal eDP panel stays dark on driver load. This patch treats iMac11,2 the same as iMac10,1, so the eDP panel stays active. Additional steps: Kernel boot parameter radeon.nomodeset=0 required to keep the eDP panel active. This patch is an extension of commit 564d8a2cf3ab ("drm/radeon: Fix eDP for single-display iMac10,1 (v2)") Link: https://lore.kernel.org/all/lsq.1507553064.833262317@xxxxxxxxxxxxxxx/ Signed-off-by: Mark Hawrylak <mark.hawrylak@xxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/radeon/atombios_encoders.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -2191,11 +2191,12 @@ int radeon_atom_pick_dig_encoder(struct /* * On DCE32 any encoder can drive any block so usually just use crtc id, - * but Apple thinks different at least on iMac10,1, so there use linkb, + * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb, * otherwise the internal eDP panel will stay dark. */ if (ASIC_IS_DCE32(rdev)) { - if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1")) + if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") || + dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) enc_idx = (dig->linkb) ? 1 : 0; else enc_idx = radeon_crtc->crtc_id;