From 9101a0205c897fea28e6a3d875111a83ad7f7732 Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@linux.ie>
Date: Sun, 24 Aug 2008 16:54:43 +1000
Subject: [PATCH] libdrm: add udev support.

This patch allows you to --enable-udev, and will avoid having libdrm
make device nodes. If you are using udev, you should really --enable-udev
your libdrm.
---
 configure.ac     |  7 +++++++
 libdrm/xf86drm.c | 25 +++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/configure.ac b/configure.ac
index 1cf877d..0cf0974 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,6 +34,9 @@ AC_SYS_LARGEFILE
 
 pkgconfigdir=${libdir}/pkgconfig
 AC_SUBST(pkgconfigdir)
+AC_ARG_ENABLE(udev,	AS_HELP_STRING([--enable-udev],
+				[Enable support for using udev instead of mknod (default: disabled)]),
+				[UDEV=$enableval], [UDEV=no])
 
 
 dnl ===========================================================================
@@ -101,6 +104,10 @@ AC_CACHE_CHECK([for supported warning flags], libdrm_cv_warn_cflags, [
 	AC_MSG_CHECKING([which warning flags were supported])])
 WARN_CFLAGS="$libdrm_cv_warn_cflags"
 
+if test "x$UDEV" = xyes; then
+	AC_DEFINE(UDEV, 1, [Have UDEV support])
+fi
+
 AC_SUBST(WARN_CFLAGS)
 AC_OUTPUT([
 	Makefile
diff --git a/libdrm/xf86drm.c b/libdrm/xf86drm.c
index 7202c8d..c36f196 100644
--- a/libdrm/xf86drm.c
+++ b/libdrm/xf86drm.c
@@ -297,6 +297,7 @@ static int drmOpenDevice(long dev, int minor)
 	group = (serv_group >= 0) ? serv_group : DRM_DEV_GID;
     }
 
+#if !defined(UDEV)
     if (stat(DRM_DIR_NAME, &st)) {
 	if (!isroot)
 	    return DRM_ERR_NOT_ROOT;
@@ -317,6 +318,30 @@ static int drmOpenDevice(long dev, int minor)
 	chown(buf, user, group);
 	chmod(buf, devmode);
     }
+#else
+    /* if we modprobed then wait for udev */
+    {
+	int udev_count = 0;
+wait_for_udev:
+        if (stat(DRM_DIR_NAME, &st)) {
+		usleep(20);
+		udev_count++;
+
+		if (udev_count == 50)
+			return -1;
+		goto wait_for_udev;
+	}
+
+    	if (stat(buf, &st)) {
+		usleep(20);
+		udev_count++;
+
+		if (udev_count == 50)
+			return -1;
+		goto wait_for_udev;
+    	}
+    }
+#endif
 
     fd = open(buf, O_RDWR, 0);
     drmMsg("drmOpenDevice: open result is %d, (%s)\n",
-- 
2.7.4