[Mesa-dev] [RFC v5 08/19] egl/x11: Re-allocate buffers if format is suboptimal

[Louis-Francis Ratté-Boulianne]

If PresentCompleteNotify event says the pixmap was presented
with mode PresentCompleteModeSuboptimalCopy, it means the pixmap
could possibly have been flipped instead if allocated with a
different format/modifier.

Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb at collabora.com>
---
 src/egl/drivers/dri2/egl_dri2.c          |  2 ++
 src/egl/drivers/dri2/egl_dri2.h          |  2 ++
 src/egl/drivers/dri2/platform_x11_dri3.c |  3 +++
 src/loader/loader_dri3_helper.c          | 27 ++++++++++++++++++++++++++-
 src/loader/loader_dri3_helper.h          |  2 ++
 5 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index b213bc76d4..611bfa5aed 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -879,6 +879,8 @@ dri2_setup_extensions(_EGLDisplay *disp)
    dri2_dpy->multibuffers_available =
       (dri2_dpy->dri3_major_version > 1 || (dri2_dpy->dri3_major_version == 1 &&
                                             dri2_dpy->dri3_minor_version >= 1)) &&
+      (dri2_dpy->present_major_version > 1 || (dri2_dpy->present_major_version == 1 &&
+                                               dri2_dpy->present_minor_version >= 1)) &&
       (dri2_dpy->image && dri2_dpy->image->base.version >= 15);
 #endif
 
diff --git a/src/egl/drivers/dri2/egl_dri2.h b/src/egl/drivers/dri2/egl_dri2.h
index 4a2581e52d..35b9777edb 100644
--- a/src/egl/drivers/dri2/egl_dri2.h
+++ b/src/egl/drivers/dri2/egl_dri2.h
@@ -200,6 +200,8 @@ struct dri2_egl_display
    bool                     multibuffers_available;
    int                      dri3_major_version;
    int                      dri3_minor_version;
+   int                      present_major_version;
+   int                      present_minor_version;
    struct loader_dri3_extensions loader_dri3_ext;
 #endif
 #endif
diff --git a/src/egl/drivers/dri2/platform_x11_dri3.c b/src/egl/drivers/dri2/platform_x11_dri3.c
index aa20fdb4b4..b61e50cb21 100644
--- a/src/egl/drivers/dri2/platform_x11_dri3.c
+++ b/src/egl/drivers/dri2/platform_x11_dri3.c
@@ -553,6 +553,9 @@ dri3_x11_connect(struct dri2_egl_display *dri2_dpy)
       free(error);
       return EGL_FALSE;
    }
+
+   dri2_dpy->present_major_version = present_query->major_version;
+   dri2_dpy->present_minor_version = present_query->minor_version;
    free(present_query);
 
    dri2_dpy->fd = loader_dri3_open(dri2_dpy->conn, dri2_dpy->screen->root, 0);
diff --git a/src/loader/loader_dri3_helper.c b/src/loader/loader_dri3_helper.c
index 02e00d82c5..d5a7621423 100644
--- a/src/loader/loader_dri3_helper.c
+++ b/src/loader/loader_dri3_helper.c
@@ -372,10 +372,22 @@ dri3_handle_present_event(struct loader_dri3_drawable *draw,
          switch (ce->mode) {
          case XCB_PRESENT_COMPLETE_MODE_FLIP:
             draw->flipping = true;
+            for (int b = 0; b < sizeof(draw->buffers) / sizeof(draw->buffers[0]); b++) {
+               if (draw->buffers[b])
+                  draw->buffers[b]->realloc_suboptimal = true;
+            }
             break;
          case XCB_PRESENT_COMPLETE_MODE_COPY:
             draw->flipping = false;
             break;
+#if XCB_PRESENT_MAJOR_VERSION > 1 || (XCB_PRESENT_MAJOR_VERSION == 1 && XCB_PRESENT_MINOR_VERSION >= 1)
+         case XCB_PRESENT_COMPLETE_MODE_SUBOPTIMAL_COPY:
+            draw->flipping = false;
+            for (int b = 0; b < sizeof(draw->buffers) / sizeof(draw->buffers[0]); b++) {
+               if (draw->buffers[b])
+                  draw->buffers[b]->suboptimal = true;
+            }
+#endif
          }
          dri3_update_num_back(draw);
 
@@ -857,6 +869,11 @@ loader_dri3_swap_buffers_msc(struct loader_dri3_drawable *draw,
       if (!loader_dri3_have_image_blit(draw) && draw->cur_blit_source != -1)
          options |= XCB_PRESENT_OPTION_COPY;
 
+#if XCB_PRESENT_MAJOR_VERSION > 1 || (XCB_PRESENT_MAJOR_VERSION == 1 && XCB_PRESENT_MINOR_VERSION >= 1)
+      if (draw->multiplanes_available)
+         options  |= XCB_PRESENT_OPTION_SUBOPTIMAL;
+#endif
+
       back->busy = 1;
       back->last_swap = draw->send_sbc;
       xcb_present_pixmap(draw->conn,
@@ -1217,6 +1234,8 @@ dri3_alloc_render_buffer(struct loader_dri3_drawable *draw, unsigned int format,
    buffer->shm_fence = shm_fence;
    buffer->width = width;
    buffer->height = height;
+   buffer->suboptimal = false;
+   buffer->realloc_suboptimal = true;
 
    /* Mark the buffer as idle
     */
@@ -1550,7 +1569,8 @@ dri3_get_buffer(__DRIdrawable *driDrawable,
     * old one is the wrong size
     */
    if (!buffer || buffer->width != draw->width ||
-       buffer->height != draw->height) {
+       buffer->height != draw->height ||
+       (buffer->suboptimal && buffer->realloc_suboptimal)) {
       struct loader_dri3_buffer *new_buffer;
 
       /* Allocate the new buffers
@@ -1609,6 +1629,11 @@ dri3_get_buffer(__DRIdrawable *driDrawable,
                                           0, 0, 0);
          }
       }
+
+      /* Avoid multiple reallocations when the best we can use is a suboptimal
+       * format/modifier. */
+      new_buffer->realloc_suboptimal = buffer ? !buffer->suboptimal : true;
+
       buffer = new_buffer;
       draw->buffers[buf_id] = buffer;
    }
diff --git a/src/loader/loader_dri3_helper.h b/src/loader/loader_dri3_helper.h
index 03c874fe0d..e1307be089 100644
--- a/src/loader/loader_dri3_helper.h
+++ b/src/loader/loader_dri3_helper.h
@@ -60,6 +60,8 @@ struct loader_dri3_buffer {
    struct xshmfence *shm_fence; /* pointer to xshmfence object */
    bool         busy;           /* Set on swap, cleared on IdleNotify */
    bool         own_pixmap;     /* We allocated the pixmap ID, free on destroy */
+   bool         suboptimal;     /* Set when CompleteNotify has ModeSuboptimalCopy */
+   bool         realloc_suboptimal; /* Avoid constant reallocation on worst cases */
 
    uint32_t     num_planes;
    uint32_t     size;
-- 
2.13.0