compositor-drm: Only update hw cursor contents when it changes

We avoid the memcpy, gbm_bo_write and the drmModeSetCursor ioctl per frame.

diff --git a/src/compositor-drm.c b/src/compositor-drm.c
index ada4a03..7cec446 100644 (file)
--- a/src/compositor-drm.c
+++ b/src/compositor-drm.c
@@ -685,21 +685,26 @@ drm_output_set_cursor(struct weston_output *output_base,
            es->geometry.width > 64 || es->geometry.height > 64)
                return;
 
-       output->current_cursor ^= 1;
-       bo = output->cursor_bo[output->current_cursor];
-       memset(buf, 0, sizeof buf);
-       stride = wl_shm_buffer_get_stride(es->buffer);
-       s = wl_shm_buffer_get_data(es->buffer);
-       for (i = 0; i < es->geometry.height; i++)
-               memcpy(buf + i * 64, s + i * stride, es->geometry.width * 4);
-
-       if (gbm_bo_write(bo, buf, sizeof buf) < 0)
-               return;
+       if (es->buffer && pixman_region32_not_empty(&es->damage)) {
+               output->current_cursor ^= 1;
+               bo = output->cursor_bo[output->current_cursor];
+               memset(buf, 0, sizeof buf);
+               stride = wl_shm_buffer_get_stride(es->buffer);
+               s = wl_shm_buffer_get_data(es->buffer);
+               for (i = 0; i < es->geometry.height; i++)
+                       memcpy(buf + i * 64, s + i * stride,
+                              es->geometry.width * 4);
+
+               weston_log("bo_write now\n");
+               if (gbm_bo_write(bo, buf, sizeof buf) < 0)
+                       return;
 
-       handle = gbm_bo_get_handle(bo).s32;
-       if (drmModeSetCursor(c->drm.fd, output->crtc_id, handle, 64, 64)) {
-               weston_log("failed to set cursor: %n\n");
-               return;
+               handle = gbm_bo_get_handle(bo).s32;
+               if (drmModeSetCursor(c->drm.fd,
+                                    output->crtc_id, handle, 64, 64)) {
+                       weston_log("failed to set cursor: %n\n");
+                       return;
+               }
        }
 
        x = es->geometry.x - output->base.x;