[igt-dev] [i-g-t RFC v1] tests/i915_pm_rpm: Add suspend-resume-latency test

[Jigar Bhatt]

Measuring the suspend-resume time using
tracefs, writing Suspend Started, Suspend Completed,
Resume Ended timestamp into tracefs file.
After writing it's reading from tracefs file and
measuring different, suspend and resume ,
individual must be less than 1 sec.

v1:
- Add limits.h and time.h

Signed-off-by: Jigar Bhatt <jigar.bhatt at intel.com>
---
 tests/i915/i915_pm_rpm.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/tests/i915/i915_pm_rpm.c b/tests/i915/i915_pm_rpm.c
index 694a3ea..3cc9259 100644
--- a/tests/i915/i915_pm_rpm.c
+++ b/tests/i915/i915_pm_rpm.c
@@ -53,6 +53,8 @@
 #include "igt_debugfs.h"
 #include "igt_device.h"
 #include "igt_edid.h"
+#include "limits.h"
+#include "time.h"
 
 #define MSR_PC8_RES	0x630
 #define MSR_PC9_RES	0x631
@@ -1998,6 +2000,85 @@ static int opt_handler(int opt, int opt_index, void *data)
 	return IGT_OPT_HANDLER_SUCCESS;
 }
 
+static void dpms_off(struct mode_set_data *data)
+{
+	for (int i = 0; i < data->res->count_connectors; i++) {
+		drmModeConnectorPtr c = data->connectors[i];
+
+		kmstest_set_connector_dpms(drm_fd, c, DRM_MODE_DPMS_OFF);
+	}
+}
+
+static void dpms_on(struct mode_set_data *data)
+{
+	igt_display_t display;
+
+	igt_display_require(&display, drm_fd);
+	for (int i = 0; i < data->res->count_connectors; i++) {
+		drmModeConnectorPtr c = data->connectors[i];
+
+		kmstest_set_connector_dpms(drm_fd, c, DRM_MODE_DPMS_ON);
+	}
+}
+
+static uint32_t get_trace_timestamp(char *dc_data)
+{
+	char *e;
+	long ret;
+	char *s = strchr(dc_data, ':');
+
+	assert(s);
+	s++;
+	ret = strtol(s, &e, 10);
+	assert(((ret != LONG_MIN && ret != LONG_MAX) || errno != ERANGE) &&
+		e > s && *e == '\n' && ret >= 0);
+	return ret;
+}
+
+static long get_timestamp(void)
+{
+	struct timespec start;
+
+	clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+	return (start.tv_sec * 1000000 + (start.tv_nsec / 1000));
+}
+
+static void read_trace(void)
+{
+	int fd;
+	char buf[4096];
+
+	fd = open("/sys/kernel/debug/tracing/trace", O_RDONLY);
+	igt_assert(fd > 0);
+	igt_assert(read(fd, buf, sizeof(buf)));
+	igt_assert(((float)(get_trace_timestamp(strstr(buf, "Suspend_Completed")) -
+			get_trace_timestamp(strstr(buf, "Suspend_Started"))) / 1000000) < 1);
+	igt_assert(((float)(get_trace_timestamp(strstr(buf, "Resume_Ended")) -
+			get_trace_timestamp(strstr(buf, "Suspend_Completed"))) / 1000000) < 1);
+	close(fd);
+}
+
+static void test_suspend_resume_latency(struct mode_set_data *data)
+{
+	int fd;
+	char msg[400];
+
+	fd = open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY);
+	igt_assert(fd > 0);
+	snprintf(msg, 100, "Suspend_Started : %ld", get_timestamp());
+	write(fd, msg, strlen(msg));
+	dpms_off(data);
+	igt_assert(igt_wait_for_pm_status(IGT_RUNTIME_PM_STATUS_SUSPENDED));
+	snprintf(msg, 100, "Suspend_Completed : %ld", get_timestamp());
+	write(fd, msg, strlen(msg));
+	dpms_on(data);
+	igt_assert(igt_wait_for_pm_status(IGT_RUNTIME_PM_STATUS_ACTIVE));
+	snprintf(msg, 100, "Resume_Ended : %ld", get_timestamp());
+	write(fd, msg, strlen(msg));
+	close(fd);
+	read_trace();
+}
+
 const char *help_str =
 	"  --stress\t\tMake the stress-tests more stressful.\n"
 	"  --stay\t\tDisable all screen and try to go into runtime pm. Useful for debugging.";
@@ -2147,6 +2228,11 @@ igt_main_args("", long_options, help_str, opt_handler, NULL)
 		pm_test_caching();
 	}
 
+	igt_subtest("suspend-resume-latency") {
+		test_suspend_resume_latency(&ms_data);
+	}
+
+
 	igt_fixture
 		teardown_environment(false);
 
-- 
2.8.1