target/linux/bcm27xx/patches-5.15/950-0017-drm-vc4-Leverage-the-load-tracker-on-the-BCM2711.patch

   1 From 1cc57695d3103fa93eda71bb6ba212c3e5806b4a Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Mon, 21 Jun 2021 17:19:22 +0200
   4 Subject: [PATCH] drm/vc4: Leverage the load tracker on the BCM2711
   5
   6 The load tracker was initially designed to report and warn about a load
   7 too high for the HVS. To do so, it computes for each plane the impact
   8 it's going to have on the HVS, and will warn (if it's enabled) if we go
   9 over what the hardware can process.
  10
  11 While the limits being used are a bit irrelevant to the BCM2711, the
  12 algorithm to compute the HVS load will be one component used in order to
  13 compute the core clock rate on the BCM2711.
  14
  15 Let's remove the hooks to prevent the load tracker to do its
  16 computation, but since we don't have the same limits, don't check them
  17 against them, and prevent the debugfs file to enable it from being
  18 created.
  19
  20 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  21 ---
  22  drivers/gpu/drm/vc4/vc4_debugfs.c |  7 +++++--
  23  drivers/gpu/drm/vc4/vc4_drv.h     |  3 ---
  24  drivers/gpu/drm/vc4/vc4_kms.c     | 16 +++++-----------
  25  drivers/gpu/drm/vc4/vc4_plane.c   |  5 -----
  26  4 files changed, 10 insertions(+), 21 deletions(-)
  27
  28 --- a/drivers/gpu/drm/vc4/vc4_debugfs.c
  29 +++ b/drivers/gpu/drm/vc4/vc4_debugfs.c
  30 @@ -7,6 +7,7 @@
  31  #include <linux/circ_buf.h>
  32  #include <linux/ctype.h>
  33  #include <linux/debugfs.h>
  34 +#include <linux/platform_device.h>
  35
  36  #include "vc4_drv.h"
  37  #include "vc4_regs.h"
  38 @@ -26,8 +27,10 @@ vc4_debugfs_init(struct drm_minor *minor
  39         struct vc4_dev *vc4 = to_vc4_dev(minor->dev);
  40         struct vc4_debugfs_info_entry *entry;
  41
  42 -       debugfs_create_bool("hvs_load_tracker", S_IRUGO | S_IWUSR,
  43 -                           minor->debugfs_root, &vc4->load_tracker_enabled);
  44 +       if (!of_device_is_compatible(vc4->hvs->pdev->dev.of_node,
  45 +                                    "brcm,bcm2711-vc5"))
  46 +               debugfs_create_bool("hvs_load_tracker", S_IRUGO | S_IWUSR,
  47 +                                   minor->debugfs_root, &vc4->load_tracker_enabled);
  48
  49         list_for_each_entry(entry, &vc4->debugfs_list, link) {
  50                 drm_debugfs_create_files(&entry->info, 1,
  51 --- a/drivers/gpu/drm/vc4/vc4_drv.h
  52 +++ b/drivers/gpu/drm/vc4/vc4_drv.h
  53 @@ -202,9 +202,6 @@ struct vc4_dev {
  54
  55         int power_refcount;
  56
  57 -       /* Set to true when the load tracker is supported. */
  58 -       bool load_tracker_available;
  59 -
  60         /* Set to true when the load tracker is active. */
  61         bool load_tracker_enabled;
  62
  63 --- a/drivers/gpu/drm/vc4/vc4_kms.c
  64 +++ b/drivers/gpu/drm/vc4/vc4_kms.c
  65 @@ -554,9 +554,6 @@ static int vc4_load_tracker_atomic_check
  66         struct drm_plane *plane;
  67         int i;
  68
  69 -       if (!vc4->load_tracker_available)
  70 -               return 0;
  71 -
  72         priv_state = drm_atomic_get_private_obj_state(state,
  73                                                       &vc4->load_tracker);
  74         if (IS_ERR(priv_state))
  75 @@ -631,9 +628,6 @@ static void vc4_load_tracker_obj_fini(st
  76  {
  77         struct vc4_dev *vc4 = to_vc4_dev(dev);
  78
  79 -       if (!vc4->load_tracker_available)
  80 -               return;
  81 -
  82         drm_atomic_private_obj_fini(&vc4->load_tracker);
  83  }
  84
  85 @@ -641,9 +635,6 @@ static int vc4_load_tracker_obj_init(str
  86  {
  87         struct vc4_load_tracker_state *load_state;
  88
  89 -       if (!vc4->load_tracker_available)
  90 -               return 0;
  91 -
  92         load_state = kzalloc(sizeof(*load_state), GFP_KERNEL);
  93         if (!load_state)
  94                 return -ENOMEM;
  95 @@ -865,9 +856,12 @@ int vc4_kms_load(struct drm_device *dev)
  96                                               "brcm,bcm2711-vc5");
  97         int ret;
  98
  99 +       /*
 100 +        * The limits enforced by the load tracker aren't relevant for
 101 +        * the BCM2711, but the load tracker computations are used for
 102 +        * the core clock rate calculation.
 103 +        */
 104         if (!is_vc5) {
 105 -               vc4->load_tracker_available = true;
 106 -
 107                 /* Start with the load tracker enabled. Can be
 108                  * disabled through the debugfs load_tracker file.
 109                  */
 110 --- a/drivers/gpu/drm/vc4/vc4_plane.c
 111 +++ b/drivers/gpu/drm/vc4/vc4_plane.c
 112 @@ -525,11 +525,6 @@ static void vc4_plane_calc_load(struct d
 113         struct vc4_plane_state *vc4_state;
 114         struct drm_crtc_state *crtc_state;
 115         unsigned int vscale_factor;
 116 -       struct vc4_dev *vc4;
 117 -
 118 -       vc4 = to_vc4_dev(state->plane->dev);
 119 -       if (!vc4->load_tracker_available)
 120 -               return;
 121
 122         vc4_state = to_vc4_plane_state(state);
 123         crtc_state = drm_atomic_get_existing_crtc_state(state->state,