tests/perf: remove frequency related changes

Experience shows that most of the issues we face with periodicity of
the reports produced by the OA unit are related to power management,
not frequency.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>

1 files changed, 9 insertions, 132 deletions

diff --git a/tests/perf.c b/tests/perf.c
index f7ecf38bd..2304e6c03 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -293,12 +293,9 @@ static int card = -1;
 static int n_eus;
 
 static uint64_t test_metric_set_id = UINT64_MAX;
-static uint64_t gt_min_freq_mhz_saved = 0;
-static uint64_t gt_max_freq_mhz_saved = 0;
-static uint64_t gt_min_freq_mhz = 0;
-static uint64_t gt_max_freq_mhz = 0;
 
 static uint64_t timestamp_frequency = 12500000;
+static uint64_t gt_max_freq_mhz = 0;
 static enum drm_i915_oa_format test_oa_format;
 static bool *undefined_a_counters;
 static uint64_t oa_exp_1_millisec;
@@ -402,16 +399,6 @@ sysfs_read(const char *file)
 	return read_u64_file(buf);
 }
 
-static void
-sysfs_write(const char *file, uint64_t val)
-{
-	char buf[512];
-
-	snprintf(buf, sizeof(buf), "/sys/class/drm/card%d/%s", card, file);
-
-	write_u64_file(buf, val);
-}
-
 static char *
 read_debugfs_record(int device, const char *file, const char *key)
 {
@@ -1008,54 +995,6 @@ init_sys_info(void)
 	return try_read_u64_file(buf, &test_metric_set_id);
 }
 
-static void
-gt_frequency_range_save(void)
-{
-	gt_min_freq_mhz_saved = sysfs_read("gt_min_freq_mhz");
-	gt_max_freq_mhz_saved = sysfs_read("gt_max_freq_mhz");
-
-	gt_min_freq_mhz = gt_min_freq_mhz_saved;
-	gt_max_freq_mhz = gt_max_freq_mhz_saved;
-}
-
-static void
-gt_frequency_pin(int gt_freq_mhz)
-{
-	igt_debug("requesting pinned GT freq = %dmhz\n", gt_freq_mhz);
-
-	if (gt_freq_mhz > gt_max_freq_mhz) {
-		sysfs_write("gt_max_freq_mhz", gt_freq_mhz);
-		sysfs_write("gt_min_freq_mhz", gt_freq_mhz);
-	} else {
-		sysfs_write("gt_min_freq_mhz", gt_freq_mhz);
-		sysfs_write("gt_max_freq_mhz", gt_freq_mhz);
-	}
-	gt_min_freq_mhz = gt_freq_mhz;
-	gt_max_freq_mhz = gt_freq_mhz;
-}
-
-static void
-gt_frequency_range_restore(void)
-{
-	igt_debug("restoring GT frequency range: min = %dmhz, max =%dmhz, current: min=%dmhz, max=%dmhz\n",
-		  (int)gt_min_freq_mhz_saved,
-		  (int)gt_max_freq_mhz_saved,
-		  (int)gt_min_freq_mhz,
-		  (int)gt_max_freq_mhz);
-
-	/* Assume current min/max are the same */
-	if (gt_min_freq_mhz_saved > gt_max_freq_mhz) {
-		sysfs_write("gt_max_freq_mhz", gt_max_freq_mhz_saved);
-		sysfs_write("gt_min_freq_mhz", gt_min_freq_mhz_saved);
-	} else {
-		sysfs_write("gt_min_freq_mhz", gt_min_freq_mhz_saved);
-		sysfs_write("gt_max_freq_mhz", gt_max_freq_mhz_saved);
-	}
-
-	gt_min_freq_mhz = gt_min_freq_mhz_saved;
-	gt_max_freq_mhz = gt_max_freq_mhz_saved;
-}
-
 static int
 i915_read_reports_until_timestamp(enum drm_i915_oa_format oa_format,
 				  uint8_t *buf,
@@ -1632,33 +1571,9 @@ test_oa_formats(void)
 }
 
 static void
-test_oa_exponents(int gt_freq_mhz)
+test_oa_exponents(void)
 {
-	uint32_t freq_margin;
-
-	/* This test tries to use the sysfs interface for pinning the GT
-	 * frequency so we have another point of reference for comparing with
-	 * the clock frequency as derived from OA reports.
-	 *
-	 * This test has been finicky to stabilise while the
-	 * gt_min/max_freq_mhz files in sysfs don't seem to be a reliable
-	 * mechanism for fixing the gpu frequency.
-	 *
-	 * Since these unit tests are focused on the OA unit not the ability to
-	 * pin the frequency via sysfs we make the test account for pinning not
-	 * being reliable and read back the current frequency for each
-	 * iteration of this test to take this into account.
-	 */
-	gt_frequency_pin(gt_freq_mhz);
-
-	igt_debug("Testing OA timer exponents with requested GT frequency = %dmhz\n",
-		  gt_freq_mhz);
-
-	/* allow a +- 10% error margin when checking that the frequency
-	 * calculated from the OA reports matches the frequency according to
-	 * sysfs.
-	 */
-	freq_margin = gt_freq_mhz * 0.1;
+	igt_debug("Testing OA timer exponents\n");
 
 	/* It's asking a lot to sample with a 160 nanosecond period and the
 	 * test can fail due to buffer overflows if it wasn't possible to
@@ -1673,7 +1588,6 @@ test_oa_exponents(int gt_freq_mhz)
 		uint32_t clock_delta;
 		uint32_t freq;
 		int n_tested = 0;
-		int n_freq_matches = 0;
 
 		/* The exponent is effectively selecting a bit in the timestamp
 		 * to trigger reports on and so in practice we expect the raw
@@ -1683,15 +1597,10 @@ test_oa_exponents(int gt_freq_mhz)
 		expected_timestamp_delta = 2 << i;
 
 		for (int j = 0; n_tested < 10 && j < 100; j++) {
-			int gt_freq_mhz_0, gt_freq_mhz_1;
 			uint32_t ticks0, ticks1;
 
-			gt_freq_mhz_0 = sysfs_read("gt_act_freq_mhz");
-
-			igt_debug("ITER %d: testing OA exponent %d (period = %"PRIu64"ns) with sysfs GT freq = %dmhz +- %u\n",
-				  j, i,
-				  oa_exponent_to_ns(i),
-				  gt_freq_mhz_0, freq_margin);
+			igt_debug("ITER %d: testing OA exponent %d (period = %"PRIu64"ns)\n",
+				  j, i, oa_exponent_to_ns(i));
 
 			open_and_read_2_oa_reports(test_oa_format,
 						   i, /* exponent */
@@ -1700,16 +1609,6 @@ test_oa_exponents(int gt_freq_mhz)
 						   true); /* timer triggered
 							     reports only */
 
-			gt_freq_mhz_1 = sysfs_read("gt_act_freq_mhz");
-
-			/* If it looks like the frequency has changed according
-			 * to sysfs then skip looking at this pair of reports
-			 */
-			if (gt_freq_mhz_0 != gt_freq_mhz_1) {
-				igt_debug("skipping OA reports pair due to GT frequency change according to sysfs\n");
-				continue;
-			}
-
 			timestamp_delta = oa_report1[1] - oa_report0[1];
 			igt_assert_neq(timestamp_delta, 0);
 
@@ -1732,31 +1631,13 @@ test_oa_exponents(int gt_freq_mhz)
 			igt_debug("ITER %d: time delta = %"PRIu32"(ns) clock delta = %"PRIu32" freq = %"PRIu32"(mhz)\n",
 				  j, time_delta, clock_delta, freq);
 
-                        if (freq < (gt_freq_mhz_1 + freq_margin) &&
-                            freq > (gt_freq_mhz_1 - freq_margin))
-				n_freq_matches++;
-
 			n_tested++;
 		}
 
 		if (n_tested < 10)
 			igt_debug("sysfs frequency pinning too unstable for cross-referencing with OA derived frequency");
 		igt_assert_eq(n_tested, 10);
-
-		igt_debug("number of iterations with expected clock frequency = %d\n",
-			  n_freq_matches);
-
-		/* Don't assert the calculated frequency for extremely short
-		 * durations.
-		 *
-		 * Allow some mismatches since can't be can't be sure about
-		 * frequency changes between sysfs reads.
-		 */
-		if (i > 3)
-			igt_assert(n_freq_matches >= 7);
 	}
-
-	gt_frequency_range_restore();
 }
 
 /* The OA exponent selects a timestamp counter bit to trigger reports on.
@@ -3978,11 +3859,11 @@ igt_main
 
 		igt_require(init_sys_info());
 
-		gt_frequency_range_save();
-
 		write_u64_file("/proc/sys/dev/i915/perf_stream_paranoid", 1);
 		write_u64_file("/proc/sys/dev/i915/oa_max_sample_rate", 100000);
 
+		gt_max_freq_mhz = sysfs_read("gt_boost_freq_mhz");
+
 		render_copy = igt_get_render_copyfunc(devid);
 		igt_require_f(render_copy, "no render-copy function\n");
 	}
@@ -4009,10 +3890,8 @@ igt_main
 		test_invalid_oa_exponent();
 	igt_subtest("low-oa-exponent-permissions")
 		test_low_oa_exponent_permissions();
-	igt_subtest("oa-exponents") {
-		test_oa_exponents(450);
-		test_oa_exponents(550);
-	}
+	igt_subtest("oa-exponents")
+		test_oa_exponents();
 
 	igt_subtest("per-context-mode-unprivileged") {
 		igt_require(IS_HASWELL(devid));
@@ -4078,8 +3957,6 @@ igt_main
 		write_u64_file("/proc/sys/dev/i915/oa_max_sample_rate", 100000);
 		write_u64_file("/proc/sys/dev/i915/perf_stream_paranoid", 1);
 
-		gt_frequency_range_restore();
-
 		close(drm_fd);
 	}
 }