target/linux/bcm27xx/patches-5.15/950-0757-drm-vc4-kms-Warn-if-we-have-an-incompatible-muxing-s.patch

   1 From 87157f42cd40d9302ad2ebae582768b52c46c8e0 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Fri, 4 Mar 2022 15:59:08 +0100
   4 Subject: [PATCH] drm/vc4: kms: Warn if we have an incompatible muxing
   5  setup
   6
   7 The documentation explicitly states we must prevent the output
   8 2 and 3 from feeding from the same HVS channel.
   9
  10 Let's add a warning to make some noise if we ever find ourselves in such
  11 a case.
  12
  13 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  14 ---
  15  drivers/gpu/drm/vc4/vc4_kms.c | 3 +++
  16  1 file changed, 3 insertions(+)
  17
  18 --- a/drivers/gpu/drm/vc4/vc4_kms.c
  19 +++ b/drivers/gpu/drm/vc4/vc4_kms.c
  20 @@ -293,6 +293,9 @@ static void vc5_hvs_pv_muxing_commit(str
  21
  22                 switch (vc4_crtc->data->hvs_output) {
  23                 case 2:
  24 +                       WARN_ON(VC4_GET_FIELD(HVS_READ(SCALER_DISPCTRL),
  25 +                                             SCALER_DISPCTRL_DSP3_MUX) == channel);
  26 +
  27                         mux = (channel == 2) ? 0 : 1;
  28                         reg = HVS_READ(SCALER_DISPECTRL);
  29                         HVS_WRITE(SCALER_DISPECTRL,