From fc508eabe2ed808c4b2258bdbbab5940b8c9a0f8 Mon Sep 17 00:00:00 2001
From: Anthony Pesch <[EMAIL REDACTED]>
Date: Sun, 23 May 2021 15:59:20 -0400
Subject: [PATCH] kmsdrm: remove redundant modeset_pending flag
this variable was added in commit 2067a7db8e4a36ba40ab34a55b3166ca28638a60 and
ultimately tracks if this is a surface's first present. checking if the current
bo is NULL provides the same functionality and cuts down on a redundant piece
of state potentially getting out of sync in the future
---
src/video/kmsdrm/SDL_kmsdrmopengles.c | 88 +++++++++++++--------------
src/video/kmsdrm/SDL_kmsdrmvideo.c | 6 --
src/video/kmsdrm/SDL_kmsdrmvideo.h | 2 -
3 files changed, 41 insertions(+), 55 deletions(-)
diff --git a/src/video/kmsdrm/SDL_kmsdrmopengles.c b/src/video/kmsdrm/SDL_kmsdrmopengles.c
index 7b28c55bc..55a53df76 100644
--- a/src/video/kmsdrm/SDL_kmsdrmopengles.c
+++ b/src/video/kmsdrm/SDL_kmsdrmopengles.c
@@ -141,64 +141,58 @@ KMSDRM_GLES_SwapWindow(_THIS, SDL_Window * window) {
return 0;
}
- /* Do we have a modeset pending? If so, configure the new mode on the CRTC.
- Has to be done before next pageflip issues, so the buffer with the
- new size is big enough for preventing CRTC from reading out of bounds. */
- if (dispdata->modeset_pending) {
-
+ if (!windata->bo) {
+ /* On the first swap, immediately present the new front buffer. Before
+ drmModePageFlip can be used the CRTC has to be configured to use
+ the current connector and mode with drmModeSetCrtc */
ret = KMSDRM_drmModeSetCrtc(viddata->drm_fd,
dispdata->crtc->crtc_id, fb_info->fb_id, 0, 0,
&dispdata->connector->connector_id, 1, &dispdata->mode);
- dispdata->modeset_pending = SDL_FALSE;
-
if (ret) {
SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not set videomode on CRTC.");
return 0;
}
+ } else {
+ /* On subsequent swaps, queue the new front buffer to be flipped during
+ the next vertical blank
+
+ Remember: drmModePageFlip() never blocks, it just issues the flip,
+ which will be done during the next vblank, or immediately if
+ we pass the DRM_MODE_PAGE_FLIP_ASYNC flag.
+ Since calling drmModePageFlip() will return EBUSY if we call it
+ without having completed the last issued flip, we must pass the
+ DRM_MODE_PAGE_FLIP_ASYNC if we don't block on EGL (egl_swapinterval = 0).
+ That makes it flip immediately, without waiting for the next vblank
+ to do so, so even if we don't block on EGL, the flip will have completed
+ when we get here again. */
+ if (_this->egl_data->egl_swapinterval == 0 && viddata->async_pageflip_support) {
+ flip_flags |= DRM_MODE_PAGE_FLIP_ASYNC;
+ }
- /* It's OK to return now if we have done a drmModeSetCrtc(),
- it has done the pageflip and blocked until it was done. */
- return 1;
- }
-
- /* Issue pageflip on the next front buffer.
- Remember: drmModePageFlip() never blocks, it just issues the flip,
- which will be done during the next vblank, or immediately if
- we pass the DRM_MODE_PAGE_FLIP_ASYNC flag.
- Since calling drmModePageFlip() will return EBUSY if we call it
- without having completed the last issued flip, we must pass the
- DRM_MODE_PAGE_FLIP_ASYNC if we don't block on EGL (egl_swapinterval = 0).
- That makes it flip immediately, without waiting for the next vblank
- to do so, so even if we don't block on EGL, the flip will have completed
- when we get here again. */
-
- if (_this->egl_data->egl_swapinterval == 0 && viddata->async_pageflip_support) {
- flip_flags |= DRM_MODE_PAGE_FLIP_ASYNC;
- }
-
- ret = KMSDRM_drmModePageFlip(viddata->drm_fd, dispdata->crtc->crtc_id,
- fb_info->fb_id, flip_flags, &windata->waiting_for_flip);
+ ret = KMSDRM_drmModePageFlip(viddata->drm_fd, dispdata->crtc->crtc_id,
+ fb_info->fb_id, flip_flags, &windata->waiting_for_flip);
- if (ret == 0) {
- windata->waiting_for_flip = SDL_TRUE;
- } else {
- SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not queue pageflip: %d", ret);
- }
+ if (ret == 0) {
+ windata->waiting_for_flip = SDL_TRUE;
+ } else {
+ SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not queue pageflip: %d", ret);
+ }
- /* Wait immediately for vsync (as if we only had two buffers).
- Even if we are already doing a WaitPageflip at the begining of this
- function, this is NOT redundant because here we wait immediately
- after submitting the image to the screen, reducing lag, and if
- we have waited here, there won't be a pending pageflip so the
- WaitPageflip at the beggining of this function will be a no-op.
- Just leave it here and don't worry.
- Run your SDL2 program with "SDL_KMSDRM_DOUBLE_BUFFER=1 <program_name>"
- to enable this. */
- if (windata->double_buffer) {
- if (!KMSDRM_WaitPageflip(_this, windata)) {
- SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Immediate wait for previous pageflip failed");
- return 0;
+ /* Wait immediately for vsync (as if we only had two buffers).
+ Even if we are already doing a WaitPageflip at the begining of this
+ function, this is NOT redundant because here we wait immediately
+ after submitting the image to the screen, reducing lag, and if
+ we have waited here, there won't be a pending pageflip so the
+ WaitPageflip at the beggining of this function will be a no-op.
+ Just leave it here and don't worry.
+ Run your SDL2 program with "SDL_KMSDRM_DOUBLE_BUFFER=1 <program_name>"
+ to enable this. */
+ if (windata->double_buffer) {
+ if (!KMSDRM_WaitPageflip(_this, windata)) {
+ SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Immediate wait for previous pageflip failed");
+ return 0;
+ }
}
}
diff --git a/src/video/kmsdrm/SDL_kmsdrmvideo.c b/src/video/kmsdrm/SDL_kmsdrmvideo.c
index 3f9de064e..56c5ef972 100644
--- a/src/video/kmsdrm/SDL_kmsdrmvideo.c
+++ b/src/video/kmsdrm/SDL_kmsdrmvideo.c
@@ -551,7 +551,6 @@ void KMSDRM_AddDisplay (_THIS, drmModeConnector *connector, drmModeRes *resource
/* Initialize some of the members of the new display's driverdata
to sane values. */
- dispdata->modeset_pending = SDL_FALSE;
dispdata->cursor_bo = NULL;
/* Since we create and show the default cursor on KMSDRM_InitMouse(),
@@ -1073,7 +1072,6 @@ KMSDRM_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
/* Take note of the new mode to be set, and leave the CRTC modeset pending
so it's done in SwapWindow. */
dispdata->mode = conn->modes[modedata->mode_index];
- dispdata->modeset_pending = SDL_TRUE;
for (i = 0; i < viddata->num_windows; i++) {
SDL_Window *window = viddata->windows[i];
@@ -1256,9 +1254,6 @@ KMSDRM_CreateWindow(_THIS, SDL_Window * window)
dispdata->mode = dispdata->original_mode;
}
- /* Take note to do the modesettng on the CRTC in SwapWindow. */
- dispdata->modeset_pending = SDL_TRUE;
-
/* Create the window surfaces with the size we have just chosen.
Needs the window diverdata in place. */
if ((ret = KMSDRM_CreateSurfaces(_this, window))) {
@@ -1348,7 +1343,6 @@ KMSDRM_ReconfigureWindow( _THIS, SDL_Window * window)
/* Recreate the GBM (and EGL) surfaces, and mark the CRTC mode/fb setting
as pending so it's done on SwapWindow. */
KMSDRM_CreateSurfaces(_this, window);
- dispdata->modeset_pending = SDL_TRUE;
/* Tell app about the size we have determined for the window,
so SDL pre-scales to that size for us. */
diff --git a/src/video/kmsdrm/SDL_kmsdrmvideo.h b/src/video/kmsdrm/SDL_kmsdrmvideo.h
index 18e90abc2..c82a849df 100644
--- a/src/video/kmsdrm/SDL_kmsdrmvideo.h
+++ b/src/video/kmsdrm/SDL_kmsdrmvideo.h
@@ -80,8 +80,6 @@ typedef struct SDL_DisplayData
uint64_t cursor_w, cursor_h;
SDL_bool default_cursor_init;
- SDL_bool modeset_pending;
-
} SDL_DisplayData;
typedef struct SDL_WindowData