target/linux/bcm27xx/patches-5.15/950-0597-drm-vc4-dpi-Ensure-a-default-format-is-selected.patch

   1 From 368bba37e67b4589b9286b2f68e6487acd5c0f79 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 2 Dec 2021 18:28:29 +0000
   4 Subject: [PATCH] drm/vc4: dpi: Ensure a default format is selected
   5
   6 In a couple of error/incomplete configuration cases, the
   7 DPI_FORMAT bits wouldn't get set.
   8
   9 Adopt a default of RGB666 in all these cases.
  10
  11 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  12 ---
  13  drivers/gpu/drm/vc4/vc4_dpi.c | 13 +++++++++----
  14  1 file changed, 9 insertions(+), 4 deletions(-)
  15
  16 --- a/drivers/gpu/drm/vc4/vc4_dpi.c
  17 +++ b/drivers/gpu/drm/vc4/vc4_dpi.c
  18 @@ -172,6 +172,10 @@ static void vc4_dpi_encoder_enable(struc
  19                                                 DPI_FORMAT);
  20                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
  21                                 break;
  22 +                       default:
  23 +                               DRM_ERROR("Unknown media bus format %d\n",
  24 +                                         bus_format);
  25 +                               fallthrough;
  26                         case MEDIA_BUS_FMT_RGB666_1X18:
  27                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
  28                                                        DPI_FORMAT);
  29 @@ -185,11 +189,12 @@ static void vc4_dpi_encoder_enable(struc
  30                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_1,
  31                                                        DPI_FORMAT);
  32                                 break;
  33 -                       default:
  34 -                               DRM_ERROR("Unknown media bus format %d\n",
  35 -                                         bus_format);
  36 -                               break;
  37                         }
  38 +               } else {
  39 +                       /* Default to 18bit if no connector found. */
  40 +                       dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
  41 +                                              DPI_FORMAT);
  42 +
  43                 }
  44
  45                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)