[Mesa-dev] [PATCH] pipe_loader: Try to make a connection with the X server before probing pciids

[Tom Stellard]

When X is running it is neccesary for pipe_loader to authenticate with
DRM, in order to be able to use the device.

This makes it possible to run OpenCL programs while X is running.
---
 configure.ac                                       |    6 ++
 .../auxiliary/pipe-loader/pipe_loader_drm.c        |   57 ++++++++++++++++++++
 2 files changed, 63 insertions(+), 0 deletions(-)

diff --git a/configure.ac b/configure.ac
index 10216a3..35cc579 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2084,6 +2084,12 @@ if test "x$enable_gallium_loader" = xyes; then
 
     if test "x$enable_gallium_drm_loader" = xyes; then
         GALLIUM_PIPE_LOADER_DEFINES="$GALLIUM_PIPE_LOADER_DEFINES -DHAVE_PIPE_LOADER_DRM"
+        PKG_CHECK_MODULES([GALLIUM_PIPE_LOADER_XCB], [x11-xcb xcb-dri2],
+                          pipe_loader_have_xcb=yes, pipe_loader_have_xcb=no)
+        if test "x$pipe_loader_have_xcb" = xyes; then
+            GALLIUM_PIPE_LOADER_DEFINES="$GALLIUM_PIPE_LOADER_DEFINES -DPIPE_LOADER_HAVE_XCB"
+            GALLIUM_PIPE_LOADER_LIBS="$GALLIUM_PIPE_LOADER_LIBS $GALLIUM_PIPE_LOADER_XCB_LIBS $LIBDRM_LIBS"
+        fi
     fi
 
     AC_SUBST([GALLIUM_PIPE_LOADER_DEFINES])
diff --git a/src/gallium/auxiliary/pipe-loader/pipe_loader_drm.c b/src/gallium/auxiliary/pipe-loader/pipe_loader_drm.c
index 518f3da..6af455c 100644
--- a/src/gallium/auxiliary/pipe-loader/pipe_loader_drm.c
+++ b/src/gallium/auxiliary/pipe-loader/pipe_loader_drm.c
@@ -35,6 +35,13 @@
 #include <libudev.h>
 #include <xf86drm.h>
 
+#ifdef PIPE_LOADER_HAVE_XCB
+
+#include <X11/Xlib-xcb.h>
+#include <xcb/dri2.h>
+
+#endif
+
 #include "state_tracker/drm_driver.h"
 #include "pipe_loader_priv.h"
 
@@ -132,6 +139,56 @@ pipe_loader_drm_probe_fd(struct pipe_loader_device **dev, int fd)
 {
    struct pipe_loader_drm_device *ddev = CALLOC_STRUCT(pipe_loader_drm_device);
 
+#if PIPE_LOADER_HAVE_XCB
+   // Try authenticate with the X server to give us access to devices that X
+   // is running on.
+   Display *disp;
+   xcb_connection_t *xcb_conn;
+   xcb_screen_iterator_t s;
+   xcb_dri2_connect_cookie_t connect_cookie;
+   xcb_dri2_connect_reply_t *connect;
+   drm_magic_t magic;
+   xcb_dri2_authenticate_cookie_t authenticate_cookie;
+   xcb_dri2_authenticate_reply_t *authenticate;
+
+   disp = XOpenDisplay(NULL);
+
+   if (!disp)
+      goto done;
+
+   xcb_conn = XGetXCBConnection(disp);
+
+   if(!xcb_conn)
+      goto done;
+
+   s = xcb_setup_roots_iterator(xcb_get_setup(xcb_conn));
+   connect_cookie = xcb_dri2_connect_unchecked(xcb_conn, s.data->root,
+                                               XCB_DRI2_DRIVER_TYPE_DRI);
+   connect = xcb_dri2_connect_reply(xcb_conn, connect_cookie, NULL);
+
+   if (!connect || connect->driver_name_length
+                   + connect->device_name_length == 0) {
+
+      goto free_connect;
+   }
+
+   if (drmGetMagic(fd, &magic))
+      goto free_connect;
+
+   authenticate_cookie = xcb_dri2_authenticate_unchecked(xcb_conn,
+                                                         s.data->root,
+                                                         magic);
+   authenticate = xcb_dri2_authenticate_reply(xcb_conn,
+                                              authenticate_cookie,
+                                              NULL);
+
+   FREE(authenticate);
+free_connect:
+   FREE(connect);
+done:
+
+#endif
+
    ddev->base.type = PIPE_LOADER_DEVICE_PCI;
    ddev->base.ops = &pipe_loader_drm_ops;
    ddev->fd = fd;
-- 
1.7.7.6