lib: Print other clients when DRM_SET_MASTER fails

It looks like there are some rogue processes running in CI that prevent
DRM_MASTER from being obtained. Dump the list of clients on failure to
make it more obvious what is being left behind.

v2: Fix up gtkdocs, meson build

References: https://bugs.freedesktop.org/show_bug.cgi?id=104157
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

6 files changed, 119 insertions, 2 deletions

diff --git a/docs/reference/intel-gpu-tools/intel-gpu-tools-docs.xml b/docs/reference/intel-gpu-tools/intel-gpu-tools-docs.xml
index 8d77cecd..7d9efd77 100644
--- a/docs/reference/intel-gpu-tools/intel-gpu-tools-docs.xml
+++ b/docs/reference/intel-gpu-tools/intel-gpu-tools-docs.xml
@@ -22,6 +22,7 @@
     <xi:include href="xml/igt_chamelium.xml"/>
     <xi:include href="xml/igt_core.xml"/>
     <xi:include href="xml/igt_debugfs.xml"/>
+    <xi:include href="xml/igt_device.xml"/>
     <xi:include href="xml/igt_draw.xml"/>
     <xi:include href="xml/igt_dummyload.xml"/>
     <xi:include href="xml/igt_fb.xml"/>
diff --git a/lib/Makefile.sources b/lib/Makefile.sources
index 06852813..86fbfeef 100644
--- a/lib/Makefile.sources
+++ b/lib/Makefile.sources
@@ -15,6 +15,8 @@ lib_source_list =	 	\
 	igt.h			\
 	igt_debugfs.c		\
 	igt_debugfs.h		\
+	igt_device.c		\
+	igt_device.h		\
 	igt_aux.c		\
 	igt_aux.h		\
 	igt_edid_template.h	\
diff --git a/lib/drmtest.c b/lib/drmtest.c
index ef2f772e..b2d8150f 100644
--- a/lib/drmtest.c
+++ b/lib/drmtest.c
@@ -51,6 +51,7 @@
 #include "intel_chipset.h"
 #include "intel_io.h"
 #include "igt_debugfs.h"
+#include "igt_device.h"
 #include "igt_gt.h"
 #include "igt_kmod.h"
 #include "version.h"
@@ -423,8 +424,7 @@ int drm_open_driver_master(int chipset)
 {
 	int fd = drm_open_driver(chipset);
 
-	igt_require_f(drmSetMaster(fd) == 0, "Can't become DRM master, "
-		      "please check if no other DRM client is running.\n");
+	igt_device_set_master(fd);
 
 	return fd;
 }
diff --git a/lib/igt_device.c b/lib/igt_device.c
new file mode 100644
index 00000000..8a2dd0e3
--- /dev/null
+++ b/lib/igt_device.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include "igt.h"
+#include "igt_device.h"
+
+int __igt_device_set_master(int fd)
+{
+	int err;
+
+	err = 0;
+	if (drmIoctl(fd, DRM_IOCTL_SET_MASTER, NULL))
+		err = -errno;
+
+	errno = 0;
+	return err;
+}
+
+/**
+ * igt_device_set_master: Set the device fd to be DRM master
+ * @fd: the device
+ *
+ * Tell the kernel to make this device fd become DRM master or skip the test.
+ */
+void igt_device_set_master(int fd)
+{
+	if (__igt_device_set_master(fd)) {
+		igt_debugfs_dump(fd, "clients");
+		igt_require_f(__igt_device_set_master(fd) == 0,
+			      "Can't become DRM master, "
+			      "please check if no other DRM client is running.\n");
+	}
+}
+
+int __igt_device_drop_master(int fd)
+{
+	int err;
+
+	err = 0;
+	if (drmIoctl(fd, DRM_IOCTL_DROP_MASTER, NULL))
+		err = -errno;
+
+	errno = 0;
+	return err;
+}
+
+/**
+ * igt_device_drop_master: Drop DRM master
+ * @fd: the device
+ *
+ * Tell the kernel we no longer want this device fd to be the DRM master;
+ * asserting that we lose the privilege.
+ */
+void igt_device_drop_master(int fd)
+{
+	igt_assert_eq(__igt_device_drop_master(fd), 0);
+}
diff --git a/lib/igt_device.h b/lib/igt_device.h
new file mode 100644
index 00000000..2995f969
--- /dev/null
+++ b/lib/igt_device.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __IGT_DEVICE_H__
+#define __IGT_DEVICE_H__
+
+int __igt_device_set_master(int fd);
+void igt_device_set_master(int fd);
+
+int __igt_device_drop_master(int fd);
+void igt_device_drop_master(int fd);
+
+#endif /* __IGT_DEVICE_H__ */
diff --git a/lib/meson.build b/lib/meson.build
index 42da7185..a32fe6d5 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -10,6 +10,7 @@ lib_headers = [
 	'i915_pciids.h',
 	'igt.h',
 	'igt_debugfs.h',
+	'igt_device.h',
 	'igt_aux.h',
 	'igt_edid_template.h',
 	'igt_gt.h',
@@ -57,6 +58,7 @@ lib_sources = [
 	'i915/gem_scheduler.c',
 	'i915/gem_submission.c',
 	'igt_debugfs.c',
+	'igt_device.c',
 	'igt_aux.c',
 	'igt_gt.c',
 	'igt_gvt.c',