[PATCH v3 6/7] video: Only dcache flush damaged lines
Alexander Graf
agraf at csgraf.de
Fri Dec 30 20:58:27 CET 2022
Now that we have a damage area tells us which parts of the frame buffer
actually need updating, let's only dcache flush those on video_sync()
calls. With this optimization in place, frame buffer updates - especially
on large screen such as 4k displays - speed up significantly.
Signed-off-by: Alexander Graf <agraf at csgraf.de>
Reported-by: Da Xue <da at libre.computer>
---
v1 -> v2:
- Fix dcache range; we were flushing too much before
- Remove ifdefs
---
drivers/video/video-uclass.c | 51 ++++++++++++++++++++++++++++++------
1 file changed, 43 insertions(+), 8 deletions(-)
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index f1fbeaadcb..bf93f524c7 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -297,9 +297,45 @@ int video_damage(struct udevice *vid, int x, int y, int width, int height)
return 0;
}
+#if defined(CONFIG_ARM) && !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
+static void video_flush_dcache(struct udevice *vid)
+{
+ struct video_priv *priv = dev_get_uclass_priv(vid);
+
+ if (!priv->flush_dcache)
+ return;
+
+ if (!CONFIG_IS_ENABLED(VIDEO_DAMAGE)) {
+ flush_dcache_range((ulong)priv->fb,
+ ALIGN((ulong)priv->fb + priv->fb_size,
+ CONFIG_SYS_CACHELINE_SIZE));
+
+ return;
+ }
+
+ if (priv->damage.endx && priv->damage.endy) {
+ int lstart = priv->damage.x * VNBYTES(priv->bpix);
+ int lend = priv->damage.endx * VNBYTES(priv->bpix);
+ int y;
+
+ for (y = priv->damage.y; y < priv->damage.endy; y++) {
+ ulong fb = (ulong)priv->fb;
+ ulong start = fb + (y * priv->line_length) + lstart;
+ ulong end = start + lend - lstart;
+
+ start = ALIGN_DOWN(start, CONFIG_SYS_CACHELINE_SIZE);
+ end = ALIGN(end, CONFIG_SYS_CACHELINE_SIZE);
+
+ flush_dcache_range(start, end);
+ }
+ }
+}
+#endif
+
/* Flush video activity to the caches */
int video_sync(struct udevice *vid, bool force)
{
+ struct video_priv *priv = dev_get_uclass_priv(vid);
struct video_ops *ops = video_get_ops(vid);
int ret;
@@ -315,15 +351,8 @@ int video_sync(struct udevice *vid, bool force)
* out whether it exists? For now, ARM is safe.
*/
#if defined(CONFIG_ARM) && !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
- struct video_priv *priv = dev_get_uclass_priv(vid);
-
- if (priv->flush_dcache) {
- flush_dcache_range((ulong)priv->fb,
- ALIGN((ulong)priv->fb + priv->fb_size,
- CONFIG_SYS_CACHELINE_SIZE));
- }
+ video_flush_dcache(vid);
#elif defined(CONFIG_VIDEO_SANDBOX_SDL)
- struct video_priv *priv = dev_get_uclass_priv(vid);
static ulong last_sync;
if (force || get_timer(last_sync) > 100) {
@@ -331,6 +360,12 @@ int video_sync(struct udevice *vid, bool force)
last_sync = get_timer(0);
}
#endif
+
+ if (CONFIG_IS_ENABLED(VIDEO_DAMAGE)) {
+ priv->damage.endx = 0;
+ priv->damage.endy = 0;
+ }
+
return 0;
}
--
2.37.1 (Apple Git-137.1)
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