target/linux/bcm27xx/patches-6.1/950-1036-drm-fb-helper-Look-up-preferred-fbdev-node-number-fr.patch

   1 From 1216ea56c2e30aee4975b4dcce79ebd199afaf8f Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Mon, 9 Oct 2023 16:34:36 +0100
   4 Subject: [PATCH] drm/fb-helper: Look up preferred fbdev node number from DT
   5
   6 For situations where there are multiple DRM cards in a system,
   7 add a query of DT for "drm_fb" designations for cards to set
   8 their preferred /dev/fbN designation.
   9
  10 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  11 ---
  12  drivers/gpu/drm/drm_fb_helper.c | 11 ++++++++++-
  13  1 file changed, 10 insertions(+), 1 deletion(-)
  14
  15 --- a/drivers/gpu/drm/drm_fb_helper.c
  16 +++ b/drivers/gpu/drm/drm_fb_helper.c
  17 @@ -1932,7 +1932,7 @@ __drm_fb_helper_initial_config_and_unloc
  18         struct drm_device *dev = fb_helper->dev;
  19         struct fb_info *info;
  20         unsigned int width, height;
  21 -       int ret;
  22 +       int ret, id;
  23
  24         width = dev->mode_config.max_width;
  25         height = dev->mode_config.max_height;
  26 @@ -1967,6 +1967,15 @@ __drm_fb_helper_initial_config_and_unloc
  27          * register the fbdev emulation instance in kernel_fb_helper_list. */
  28         mutex_unlock(&fb_helper->lock);
  29
  30 +       id = of_alias_get_highest_id("drm_fb");
  31 +       if (id >= 0)
  32 +               fb_set_lowest_dynamic_fb(id + 1);
  33 +
  34 +       id = of_alias_get_id(dev->dev->of_node, "drm_fb");
  35 +       if (id >= 0) {
  36 +               info->node = id;
  37 +               info->custom_fb_num = true;
  38 +       }
  39         ret = register_framebuffer(info);
  40         if (ret < 0)
  41                 return ret;