target/linux/brcm2708/patches-4.14/950-0349-drm-vc4-Fix-oops-dereferencing-DPI-s-connector-since.patch

   1 From 2e4ad74553a929623fd09b2baf2ac73bc4adcd80 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Fri, 9 Mar 2018 15:32:56 -0800
   4 Subject: [PATCH 349/454] drm/vc4: Fix oops dereferencing DPI's connector since
   5  panel_bridge.
   6
   7 In the cleanup, I didn't notice that we needed to dereference the
   8 connector for the bus_format.  Fix the regression by looking up the
   9 first (and only) connector attached to us, and assume that its
  10 bus_format is what we want.  Some day it would be good to have that
  11 part of display_info attached to the bridge, instead.
  12
  13 v2: Fix stray whitespace change
  14
  15 Signed-off-by: Eric Anholt <eric@anholt.net>
  16 Fixes: 7b1298e05310 ("drm/vc4: Switch DPI to using the panel-bridge helper.")
  17 Link: https://patchwork.freedesktop.org/patch/msgid/20180309233256.1667-1-eric@anholt.net
  18 Reviewed-by: Sean Paul <seanpaul@chromium.org>
  19 Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
  20 (cherry picked from commit 721fe38db2010e8d475abf2c1d2bafb6dc031741)
  21 ---
  22  drivers/gpu/drm/vc4/vc4_dpi.c | 25 ++++++++++++++++++++++---
  23  1 file changed, 22 insertions(+), 3 deletions(-)
  24
  25 --- a/drivers/gpu/drm/vc4/vc4_dpi.c
  26 +++ b/drivers/gpu/drm/vc4/vc4_dpi.c
  27 @@ -96,7 +96,6 @@ struct vc4_dpi {
  28         struct platform_device *pdev;
  29
  30         struct drm_encoder *encoder;
  31 -       struct drm_connector *connector;
  32         struct drm_bridge *bridge;
  33         bool is_panel_bridge;
  34
  35 @@ -166,14 +165,31 @@ static void vc4_dpi_encoder_disable(stru
  36
  37  static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
  38  {
  39 +       struct drm_device *dev = encoder->dev;
  40         struct drm_display_mode *mode = &encoder->crtc->mode;
  41         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
  42         struct vc4_dpi *dpi = vc4_encoder->dpi;
  43 +       struct drm_connector_list_iter conn_iter;
  44 +       struct drm_connector *connector = NULL, *connector_scan;
  45         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
  46         int ret;
  47
  48 -       if (dpi->connector->display_info.num_bus_formats) {
  49 -               u32 bus_format = dpi->connector->display_info.bus_formats[0];
  50 +       /* Look up the connector attached to DPI so we can get the
  51 +        * bus_format.  Ideally the bridge would tell us the
  52 +        * bus_format we want, but it doesn't yet, so assume that it's
  53 +        * uniform throughout the bridge chain.
  54 +        */
  55 +       drm_connector_list_iter_begin(dev, &conn_iter);
  56 +       drm_for_each_connector_iter(connector_scan, &conn_iter) {
  57 +               if (connector_scan->encoder == encoder) {
  58 +                       connector = connector_scan;
  59 +                       break;
  60 +               }
  61 +       }
  62 +       drm_connector_list_iter_end(&conn_iter);
  63 +
  64 +       if (connector && connector->display_info.num_bus_formats) {
  65 +               u32 bus_format = connector->display_info.bus_formats[0];
  66
  67                 switch (bus_format) {
  68                 case MEDIA_BUS_FMT_RGB888_1X24:
  69 @@ -201,6 +217,9 @@ static void vc4_dpi_encoder_enable(struc
  70                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
  71                         break;
  72                 }
  73 +       } else {
  74 +               /* Default to 24bit if no connector found. */
  75 +               dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
  76         }
  77
  78         if (mode->flags & DRM_MODE_FLAG_NHSYNC)