egl/drm: flush before calling get_back_bo

Similar to what was done for Wayland in 58f90fd03f:
the glthread unmarhsal thread needs to be idle to avoid
concurrent calls to get_back_bo.

Also the existing code flushed after setting dri2_surf->back
to NULL so a new back buffer was always allocated by the
glthread flush:

|---------------> dri2_drm_swap_buffers
| get_back_bo (back=0x55eb93c6c488) >       # First get_back_bo call
| get_back_bo (back=0x55eb93c6c488 age: 0)<
|                                           # dri2_surf->back = NULL
|-----> FLUSH
| get_back_bo (back=nil) >                  # Another get_back_bo call
| get_back_bo (back=0x55eb93c6c4c8 age: 3)<
|-----< FLUSH
|---------------< dri2_drm_swap_buffers

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/10437
Cc: mesa-stable
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27143>
(cherry picked from commit 6f47e87a60)
This commit is contained in:
Pierre-Eric Pelloux-Prayer
2024-01-18 14:18:27 +01:00
committed by Eric Engestrom
parent e16629a285
commit 6cd32859d0
2 changed files with 8 additions and 4 deletions

View File

@@ -764,7 +764,7 @@
"description": "egl/drm: flush before calling get_back_bo",
"nominated": true,
"nomination_type": 0,
"resolution": 0,
"resolution": 1,
"main_sha": null,
"because_sha": null,
"notes": null

View File

@@ -329,6 +329,13 @@ dri2_drm_swap_buffers(_EGLDisplay *disp, _EGLSurface *draw)
if (dri2_surf->color_buffers[i].age > 0)
dri2_surf->color_buffers[i].age++;
/* Flushing must be done before get_back_bo to make sure glthread's
* unmarshalling thread is idle otherwise it might concurrently
* call get_back_bo (eg: through dri2_drm_image_get_buffers).
*/
dri2_flush_drawable_for_swapbuffers(disp, draw);
dri2_dpy->flush->invalidate(dri2_surf->dri_drawable);
/* Make sure we have a back buffer in case we're swapping without
* ever rendering. */
if (get_back_bo(dri2_surf) < 0)
@@ -338,9 +345,6 @@ dri2_drm_swap_buffers(_EGLDisplay *disp, _EGLSurface *draw)
dri2_surf->current->age = 1;
dri2_surf->back = NULL;
dri2_flush_drawable_for_swapbuffers(disp, draw);
dri2_dpy->flush->invalidate(dri2_surf->dri_drawable);
return EGL_TRUE;
}