Mesa (master): i965: Improve same-buffer restriction for imports

[Daniel Stone]

Module: Mesa
Branch: master
Commit: f58e6358bf775e21d49f7a0ea0007f1940c48217
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f58e6358bf775e21d49f7a0ea0007f1940c48217

Author: Daniel Stone <daniels at collabora.com>
Date:   Tue May 30 17:41:48 2017 +0530

i965: Improve same-buffer restriction for imports

Intel hardware requires that all planes of an image come from the same
buffer, which is currently implemented by testing that all FDs are
numerically the same.

However, when going through a winsys (e.g.) or anything which transits
FDs individually, the FDs may be different even if the underlying buffer
is the same.

Instead of checking the FDs for equality, we must check if they actually
point to the same buffer (Jason).

Reviewed-by: Varad Gautam <varad.gautam at collabora.com>
Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>

---

 src/mesa/drivers/dri/i965/intel_screen.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index 96f3016812..638a9b080b 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -841,11 +841,6 @@ intel_create_image_from_fds(__DRIscreen *dri_screen,
    if (fds == NULL || num_fds < 1)
       return NULL;
 
-   /* We only support all planes from the same bo */
-   for (i = 0; i < num_fds; i++)
-      if (fds[0] != fds[i])
-         return NULL;
-
    f = intel_image_format_lookup(fourcc);
    if (f == NULL)
       return NULL;
@@ -872,6 +867,19 @@ intel_create_image_from_fds(__DRIscreen *dri_screen,
       return NULL;
    }
 
+   /* We only support all planes from the same bo.
+    * brw_bo_gem_create_from_prime() should return the same pointer for all
+    * fds received here */
+   for (i = 1; i < num_fds; i++) {
+      struct brw_bo *aux = brw_bo_gem_create_from_prime(screen->bufmgr, fds[i]);
+      brw_bo_unreference(aux);
+      if (aux != image->bo) {
+         brw_bo_unreference(image->bo);
+         free(image);
+         return NULL;
+      }
+   }
+
    image->modifier = tiling_to_modifier(image->bo->tiling_mode);
    tiled_height = get_tiled_height(image->modifier, height);