tests: rc6 residency test

This is meant to test the sysfs entry for showing rc6 residency in
milliseconds. Remember, sysfs is a permanent interface.

v2: use new get_card interface to try "all" devices
check rc6p and rc6pp in addition to rc6

v3: rename rc6_residency.c to sysfs_rc6_residency.c
print better error messages
skip test if rc6 isn't enabled

v4: update to new sysfs names

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>

lib/drmtest.h

@@ -35,6 +35,7 @@
 #include "xf86drm.h"
 #include "intel_batchbuffer.h"
 
+int drm_get_card(int master);
 int drm_open_any(void);
 int drm_open_any_master(void);
 

tests/Makefile.am

@@ -57,6 +57,7 @@ TESTS_progs = \
 	drm_vma_limiter_cpu \
 	drm_vma_limiter_gtt \
 	drm_vma_limiter_cached \
+	sysfs_rc6_residency \
 	$(NULL)
 
 # IMPORTANT: The ZZ_ tests need to be run last!

tests/sysfs_rc6_residency.c

@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2012 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.
+ *
+ * Authors:
+ *    Ben Widawsky <ben@bwidawsk.net>
+ *
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "drmtest.h"
+
+#define SLEEP_DURATION 3000 // in milliseconds
+#define RC6_FUDGE 900 // in milliseconds
+
+static unsigned int readit(const char *path)
+{
+	unsigned int ret;
+
+	FILE *file;
+	file = fopen(path, "r");
+	if (file == NULL) {
+		fprintf(stderr, "Couldn't open %s (%d)\n", path, errno);
+		abort();
+	}
+	fscanf(file, "%u", &ret);
+	fclose(file);
+
+	return ret;
+}
+
+int main(int argc, char *argv[])
+{
+	const int device = drm_get_card(0);
+	char *path, *pathp, *pathpp;
+	int fd, ret;
+	unsigned int value1, value1p, value1pp, value2, value2p, value2pp;
+	int diff;
+
+	/* Use drm_open_any to verify device existence */
+	fd = drm_open_any();
+	close(fd);
+
+	ret = asprintf(&path, "/sys/class/drm/card%d/power/rc6_enable", device);
+	assert(ret != -1);
+
+	if (readit(path) == 0)
+		exit(EXIT_SUCCESS);
+
+	ret = asprintf(&path, "/sys/class/drm/card%d/power/rc6_residency_ms", device);
+	assert(ret != -1);
+	ret = asprintf(&pathp, "/sys/class/drm/card%d/power/rc6p_residency_ms", device);
+	assert(ret != -1);
+	ret = asprintf(&pathpp, "/sys/class/drm/card%d/power/rc6pp_residency_ms", device);
+	assert(ret != -1);
+
+	value1 = readit(path);
+	value1p = readit(pathp);
+	value1pp = readit(pathpp);
+	sleep(SLEEP_DURATION / 1000);
+	value2 = readit(path);
+	value2p = readit(pathp);
+	value2pp = readit(pathpp);
+
+	free(pathpp);
+	free(pathp);
+	free(path);
+
+	diff = (value2pp - value1pp) +
+		(value2p - value1p) +
+		(value2 - value1);
+
+	if (diff > (SLEEP_DURATION + RC6_FUDGE)) {
+		fprintf(stderr, "Diff was too high. That is unpossible\n");
+		exit(EXIT_FAILURE);
+	}
+	if (diff < (SLEEP_DURATION - RC6_FUDGE)) {
+		fprintf(stderr, "GPU was not in RC6 long enough. Check that "
+				"the GPU is as idle as possible (ie. no X, "
+				"running and running no other tests)\n");
+		exit(EXIT_FAILURE);
+	}
+
+	exit(EXIT_SUCCESS);
+}