git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From da426c4209e19b57dfda5908415d35e5f00a9670 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 4 Jan 2024 12:39:33 +0000
   4 Subject: [PATCH 0836/1085] drm/vc4: Optimise vc4_hvs_dlist_free_work to only
   5  read frcnt and active once
   6
   7 vc4_hvs_dlist_free_work was iterating through the list of stale
   8 dlist entries and reading the frame count and active flags from
   9 the hardware for each one.
  10
  11 Read the frame count and active flags once, and then use the
  12 cached value in the loop.
  13
  14 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  15 ---
  16  drivers/gpu/drm/vc4/vc4_hvs.c | 15 ++++++++++-----
  17  1 file changed, 10 insertions(+), 5 deletions(-)
  18
  19 --- a/drivers/gpu/drm/vc4/vc4_hvs.c
  20 +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
  21 @@ -855,14 +855,19 @@ static void vc4_hvs_dlist_free_work(stru
  22         struct vc4_hvs *hvs = container_of(work, struct vc4_hvs, free_dlist_work);
  23         struct vc4_hvs_dlist_allocation *cur, *next;
  24         unsigned long flags;
  25 +       bool active[3];
  26 +       u8 frcnt[3];
  27 +       int i;
  28 +
  29
  30         spin_lock_irqsave(&hvs->mm_lock, flags);
  31 +       for (i = 0; i < 3; i++) {
  32 +               frcnt[i] = vc4_hvs_get_fifo_frame_count(hvs, i);
  33 +               active[i] = vc4_hvs_check_channel_active(hvs, i);
  34 +       }
  35         list_for_each_entry_safe(cur, next, &hvs->stale_dlist_entries, node) {
  36 -               u8 frcnt;
  37 -
  38 -               frcnt = vc4_hvs_get_fifo_frame_count(hvs, cur->channel);
  39 -               if (vc4_hvs_check_channel_active(hvs, cur->channel) &&
  40 -                   !vc4_hvs_frcnt_lte(cur->target_frame_count, frcnt))
  41 +               if (active[cur->channel] &&
  42 +                   !vc4_hvs_frcnt_lte(cur->target_frame_count, frcnt[cur->channel]))
  43                         continue;
  44
  45                 vc4_hvs_free_dlist_entry_locked(hvs, cur);