When I revert this commit, the screen on my iMac11,2 works again:
https://marc.info/?l=openbsd-cvs&m=167989100718759&w=2
Index: atombios_encoders.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/drm/radeon/atombios_encoders.c,v
retrieving revision 1.19
diff -u -p -u -p -r1.19 atombios_encoders.c
--- atombios_encoders.c 27 Mar 2023 04:23:40 -0000 1.19
+++ atombios_encoders.c 18 Oct 2023 18:29:56 -0000
@@ -2122,12 +2122,11 @@ 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 and iMac11,2, so
there use linkb,
+ * but Apple thinks different at least on iMac10,1, 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") ||
- dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
+ if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1"))
enc_idx = (dig->linkb) ? 1 : 0;
else
enc_idx = radeon_crtc->crtc_id;
