bcm27xx: update 6.1 patches from RPi foundation

[openwrt/staging/xback.git] / target / linux / bcm27xx / patches-6.1 / 950-1247-drm-vc4-Optimise-vc4_hvs_dlist_free_work-to-only-rea.patch

diff --git a/target/linux/bcm27xx/patches-6.1/950-1247-drm-vc4-Optimise-vc4_hvs_dlist_free_work-to-only-rea.patch b/target/linux/bcm27xx/patches-6.1/950-1247-drm-vc4-Optimise-vc4_hvs_dlist_free_work-to-only-rea.patch
new file mode 100644 (file)
index 0000000..1e28933
--- /dev/null
+++ b/target/linux/bcm27xx/patches-6.1/950-1247-drm-vc4-Optimise-vc4_hvs_dlist_free_work-to-only-rea.patch
@@ -0,0 +1,45 @@
+From d8e53e0b83c947123c38c81d2fb5162c86d26fb5 Mon Sep 17 00:00:00 2001
+From: Dave Stevenson <dave.stevenson@raspberrypi.com>
+Date: Thu, 4 Jan 2024 12:39:33 +0000
+Subject: [PATCH 1247/1295] drm/vc4: Optimise vc4_hvs_dlist_free_work to only
+ read frcnt and active once
+
+vc4_hvs_dlist_free_work was iterating through the list of stale
+dlist entries and reading the frame count and active flags from
+the hardware for each one.
+
+Read the frame count and active flags once, and then use the
+cached value in the loop.
+
+Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
+---
+ drivers/gpu/drm/vc4/vc4_hvs.c | 15 ++++++++++-----
+ 1 file changed, 10 insertions(+), 5 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hvs.c
++++ b/drivers/gpu/drm/vc4/vc4_hvs.c
+@@ -796,14 +796,19 @@ static void vc4_hvs_dlist_free_work(stru
+       struct vc4_hvs *hvs = container_of(work, struct vc4_hvs, free_dlist_work);
+       struct vc4_hvs_dlist_allocation *cur, *next;
+       unsigned long flags;
++      bool active[3];
++      u8 frcnt[3];
++      int i;
++
+ 
+       spin_lock_irqsave(&hvs->mm_lock, flags);
++      for (i = 0; i < 3; i++) {
++              frcnt[i] = vc4_hvs_get_fifo_frame_count(hvs, i);
++              active[i] = vc4_hvs_check_channel_active(hvs, i);
++      }
+       list_for_each_entry_safe(cur, next, &hvs->stale_dlist_entries, node) {
+-              u8 frcnt;
+-
+-              frcnt = vc4_hvs_get_fifo_frame_count(hvs, cur->channel);
+-              if (vc4_hvs_check_channel_active(hvs, cur->channel) &&
+-                  !vc4_hvs_frcnt_lte(cur->target_frame_count, frcnt))
++              if (active[cur->channel] &&
++                  !vc4_hvs_frcnt_lte(cur->target_frame_count, frcnt[cur->channel]))
+                       continue;
+ 
+               vc4_hvs_free_dlist_entry_locked(hvs, cur);