From 33787db41d955f8dcafe833097f2cc87d70186ec Mon Sep 17 00:00:00 2001 From: notaz Date: Mon, 14 Mar 2022 01:17:09 +0200 Subject: [PATCH] fbdev: wait vsync after mode change, not before As it was before we were getting a full frame scanout of the old mode, while the emu (or whatever) was already writing a frame in new mode. first_write_to_front is a hack for psx. --- linux/fbdev.c | 14 ++++++++------ linux/fbdev.h | 2 +- 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/linux/fbdev.c b/linux/fbdev.c index d8d78eb..43f3010 100644 --- 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; diff --git a/linux/fbdev.h b/linux/fbdev.h index 88cd519..b2ba18f 100644 --- a/linux/fbdev.h +++ b/linux/fbdev.h @@ -5,7 +5,7 @@ void *vout_fbdev_flip(struct vout_fbdev *fbdev); void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev); 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_count); + int buffer_cnt, int first_write_to_front); void vout_fbdev_clear(struct vout_fbdev *fbdev); void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count); int vout_fbdev_get_fd(struct vout_fbdev *fbdev); -- 2.39.2