video: Only dcache flush damaged lines
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@csgraf.de>
Reported-by: Da Xue <da@libre.computer>
[Alper: Use damage.xstart/yend, IS_ENABLED()]
Co-developed-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Link: https://lore.kernel.org/u-boot/20230821135111.3558478-11-alpernebiyasak@gmail.com/
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 3933aeb..8fb3b22 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -401,6 +401,40 @@
}
#endif
+#if defined(CONFIG_ARM) && !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
+static void video_flush_dcache(struct udevice *vid, bool use_copy)
+{
+ struct video_priv *priv = dev_get_uclass_priv(vid);
+ ulong fb = use_copy ? (ulong)priv->copy_fb : (ulong)priv->fb;
+
+ if (!priv->flush_dcache)
+ return;
+
+ if (!IS_ENABLED(CONFIG_VIDEO_DAMAGE)) {
+ flush_dcache_range(fb, ALIGN(fb + priv->fb_size,
+ CONFIG_SYS_CACHELINE_SIZE));
+
+ return;
+ }
+
+ if (priv->damage.xend && priv->damage.yend) {
+ int lstart = priv->damage.xstart * VNBYTES(priv->bpix);
+ int lend = priv->damage.xend * VNBYTES(priv->bpix);
+ int y;
+
+ for (y = priv->damage.ystart; y < priv->damage.yend; y++) {
+ 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)
{
@@ -424,11 +458,10 @@
* out whether it exists? For now, ARM is safe.
*/
#if defined(CONFIG_ARM) && !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
- 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, false);
+
+ if (IS_ENABLED(CONFIG_VIDEO_COPY))
+ video_flush_dcache(vid, true);
#elif defined(CONFIG_VIDEO_SANDBOX_SDL)
sandbox_sdl_sync(priv->fb);
#endif