nv50_hdmi_enable() passes the sink's SCDC capability from its EDID straight through to nvif_outp_hdmi(). On pre-Maxwell-2 cards there is no hdmi->scdc callback, so nvkm_uoutp_mthd_hdmi() rejects the whole configuration with -EINVAL, and nv50_hdmi_enable() returns before hdmi->ctrl() runs and before the AVI and VSI infoframes are sent.
The result on such a card driving an SCDC-capable HDMI 2.0 sink is that HDMI audio silently stops working. Video is unaffected, and nothing is logged, which makes the failure hard to attribute. SCDC is optional, and the hdmi->scdc() call further down is already guarded against a missing callback. Requesting it on a card that cannot do it need not invalidate the rest of the HDMI configuration, so drop that term from the condition and let the existing guard skip SCDC alone. Giuseppe Ranieri posted a fix for this to the nouveau list on 2026-01-17, which received no review: https://ratatoskr.run/nouveau/2026/01/16963412 Fixes: 6c6abab20b99 ("drm/nouveau/disp: add output hdmi config method") Signed-off-by: Tano Dzhinski <[email protected]> --- drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c index 377d0e0cef84..9887b3898505 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c @@ -253,8 +253,7 @@ nvkm_uoutp_mthd_hdmi(struct nvkm_outp *outp, void *argv, u32 argc) if (!ior->func->hdmi || args->v0.max_ac_packet > 0x1f || - args->v0.rekey > 0x7f || - (args->v0.scdc && !ior->func->hdmi->scdc)) + args->v0.rekey > 0x7f) return -EINVAL; if (!args->v0.enable) { -- 2.43.0
