target/linux/bcm27xx/patches-5.15/950-0024-drm-vc4-Notify-the-firmware-when-DRM-is-in-charge.patch

   1 From 9e9177db83609c19bbe523cc4d20119cf09ea787 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Wed, 15 Dec 2021 10:51:17 +0100
   4 Subject: [PATCH] drm/vc4: Notify the firmware when DRM is in charge
   5
   6 Once the call to drm_fb_helper_remove_conflicting_framebuffers() has
   7 been made, simplefb has been unregistered and the KMS driver is entirely
   8 in charge of the display.
   9
  10 Thus, we can notify the firmware it can free whatever resource it was
  11 using to maintain simplefb functional.
  12
  13 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  14 Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
  15 Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
  16 Link: https://patchwork.freedesktop.org/patch/msgid/20211215095117.176435-5-maxime@cerno.tech
  17 ---
  18  drivers/gpu/drm/vc4/vc4_drv.c | 22 ++++++++++++++++++++++
  19  1 file changed, 22 insertions(+)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_drv.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_drv.c
  23 @@ -37,6 +37,8 @@
  24  #include <drm/drm_fb_helper.h>
  25  #include <drm/drm_vblank.h>
  26
  27 +#include <soc/bcm2835/raspberrypi-firmware.h>
  28 +
  29  #include "uapi/drm/vc4_drm.h"
  30
  31  #include "vc4_drv.h"
  32 @@ -217,6 +219,7 @@ static void vc4_match_add_drivers(struct
  33  static int vc4_drm_bind(struct device *dev)
  34  {
  35         struct platform_device *pdev = to_platform_device(dev);
  36 +       struct rpi_firmware *firmware = NULL;
  37         struct drm_device *drm;
  38         struct vc4_dev *vc4;
  39         struct device_node *node;
  40 @@ -253,10 +256,29 @@ static int vc4_drm_bind(struct device *d
  41         if (ret)
  42                 return ret;
  43
  44 +       node = of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware");
  45 +       if (node) {
  46 +               firmware = rpi_firmware_get(node);
  47 +               of_node_put(node);
  48 +
  49 +               if (!firmware)
  50 +                       return -EPROBE_DEFER;
  51 +       }
  52 +
  53         ret = drm_aperture_remove_framebuffers(false, &vc4_drm_driver);
  54         if (ret)
  55                 return ret;
  56
  57 +       if (firmware) {
  58 +               ret = rpi_firmware_property(firmware,
  59 +                                           RPI_FIRMWARE_NOTIFY_DISPLAY_DONE,
  60 +                                           NULL, 0);
  61 +               if (ret)
  62 +                       drm_warn(drm, "Couldn't stop firmware display driver: %d\n", ret);
  63 +
  64 +               rpi_firmware_put(firmware);
  65 +       }
  66 +
  67         ret = component_bind_all(dev, drm);
  68         if (ret)
  69                 return ret;