From 87157f42cd40d9302ad2ebae582768b52c46c8e0 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Fri, 4 Mar 2022 15:59:08 +0100 Subject: [PATCH] drm/vc4: kms: Warn if we have an incompatible muxing setup The documentation explicitly states we must prevent the output 2 and 3 from feeding from the same HVS channel. Let's add a warning to make some noise if we ever find ourselves in such a case. Signed-off-by: Maxime Ripard --- drivers/gpu/drm/vc4/vc4_kms.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/vc4/vc4_kms.c +++ b/drivers/gpu/drm/vc4/vc4_kms.c @@ -293,6 +293,9 @@ static void vc5_hvs_pv_muxing_commit(str switch (vc4_crtc->data->hvs_output) { case 2: + WARN_ON(VC4_GET_FIELD(HVS_READ(SCALER_DISPCTRL), + SCALER_DISPCTRL_DSP3_MUX) == channel); + mux = (channel == 2) ? 0 : 1; reg = HVS_READ(SCALER_DISPECTRL); HVS_WRITE(SCALER_DISPECTRL,