From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 21 Apr 2020 12:46:36 +0000 (+0100)
Subject: drm/i915/selftests: Show the full scaling curve on failure
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4ea6b1c456273c6da43a503c55f9eaec2da331cf;p=linux.git

drm/i915/selftests: Show the full scaling curve on failure

If we detect that the RPS end points do not scale perfectly, take the
time to measure all the in between values as well. We are aborting the
test, so we might as well spend the available time gathering critical
debug information instead.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200421124636.22554-1-chris@chris-wilson.co.uk
---

diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c
index e0a791eac7523..395265121e43a 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.c
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.c
@@ -484,11 +484,31 @@ int live_rps_frequency_cs(void *arg)
 		if (!scaled_within(max.freq * min.count,
 				   min.freq * max.count,
 				   2, 3)) {
+			int f;
+
 			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
 			       engine->name,
 			       max.freq * min.count,
 			       min.freq * max.count);
 			show_pcu_config(rps);
+
+			for (f = min.freq + 1; f <= rps->max_freq; f++) {
+				int act = f;
+				u64 count;
+
+				count = measure_cs_frequency_at(rps, engine, &act);
+				if (act < f)
+					break;
+
+				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
+					engine->name,
+					act, intel_gpu_freq(rps, act), count,
+					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
+								     act * min.count));
+
+				f = act; /* may skip ahead [pcu granularity] */
+			}
+
 			err = -EINVAL;
 		}
 
@@ -593,11 +613,31 @@ int live_rps_frequency_srm(void *arg)
 		if (!scaled_within(max.freq * min.count,
 				   min.freq * max.count,
 				   1, 2)) {
+			int f;
+
 			pr_err("%s: CS did not scale with frequency! scaled min:%llu, max:%llu\n",
 			       engine->name,
 			       max.freq * min.count,
 			       min.freq * max.count);
 			show_pcu_config(rps);
+
+			for (f = min.freq + 1; f <= rps->max_freq; f++) {
+				int act = f;
+				u64 count;
+
+				count = measure_frequency_at(rps, cntr, &act);
+				if (act < f)
+					break;
+
+				pr_info("%s: %x:%uMHz: %lluKHz [%d%%]\n",
+					engine->name,
+					act, intel_gpu_freq(rps, act), count,
+					(int)DIV64_U64_ROUND_CLOSEST(100 * min.freq * count,
+								     act * min.count));
+
+				f = act; /* may skip ahead [pcu granularity] */
+			}
+
 			err = -EINVAL;
 		}