egl: setup fds array correctly when exporting dmabuf

For formats with multiple planes, application will pass a num_planes
sized fds array which should be initialized properly in case fds amount
utilized by the driver is less than the number of planes.

Signed-off-by: Tapani Pälli <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 6acc99aa62a..9d8a4d9cf71 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -2652,12 +2652,24 @@ dri2_export_dma_buf_image_mesa(_EGLDriver *drv, _EGLDisplay *disp, _EGLImage *im
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
    struct dri2_egl_image *dri2_img = dri2_egl_image(img);
+   EGLint nplanes;
 
    (void) drv;
 
    if (!dri2_can_export_dma_buf_image(disp, img))
       return EGL_FALSE;
 
+   /* EGL_MESA_image_dma_buf_export spec says:
+    *    "If the number of fds is less than the number of planes, then
+    *    subsequent fd slots should contain -1."
+    */
+   if (fds) {
+      /* Query nplanes so that we know how big the given array is. */
+      dri2_dpy->image->queryImage(dri2_img->dri_image,
+                                  __DRI_IMAGE_ATTRIB_NUM_PLANES, &nplanes);
+      memset(fds, -1, nplanes * sizeof(int));
+   }
+
    /* rework later to provide multiple fds/strides/offsets */
    if (fds)
       dri2_dpy->image->queryImage(dri2_img->dri_image,