fbdev: wait vsync after mode change, not before

[libpicofe.git] / linux / fbdev.c

diff --git a/linux/fbdev.c b/linux/fbdev.c
index d8d78eb..43f3010 100644 (file)
--- a/linux/fbdev.c
+++ b/linux/fbdev.c
@@ -66,9 +66,9 @@ void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
        ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
 }
 
-/* it is recommended to call vout_fbdev_clear() before this */
 void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
-                     int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
+       int left_border, int right_border, int top_border, int bottom_border,
+       int buffer_cnt, int first_write_to_front)
 {
        int w_total = left_border + w + right_border;
        int h_total = top_border + h + bottom_border;
@@ -100,9 +100,8 @@ void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
                fbdev->fbvar_new.nonstd = 0; // can set YUV here on omapfb
                fbdev->buffer_count = buffer_cnt;
                fbdev->buffer_write = buffer_cnt > 1 ? 1 : 0;
-
-               // seems to help a bit to avoid glitches
-               vout_fbdev_wait_vsync(fbdev);
+               if (first_write_to_front)
+                       fbdev->buffer_write = 0;
 
                ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
                if (ret == -1) {
@@ -119,6 +118,9 @@ void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
                                        "multibuffering disabled\n");
                }
 
+               // omap is still using the old mode until vsync,
+               // if the caller starts to write now we may get garbage on screen
+               vout_fbdev_wait_vsync(fbdev);
        }
 
        fbdev->fb_size = w_total * h_total * bpp / 8;
@@ -210,7 +212,7 @@ struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int b
        if (*h != 0)
                req_h = *h;
 
-       pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
+       pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt, 0);
        if (pret == NULL)
                goto fail;