[PATCH 3/4] drm/i915/selftests: Check RPS controls
Chris Wilson
chris at chris-wilson.co.uk
Sun Apr 19 11:17:32 UTC 2020
Check that the GPU does respond to our RPS frequency requests by setting
our desired frequency.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/selftest_gt_pm.c | 1 +
drivers/gpu/drm/i915/gt/selftest_rps.c | 196 ++++++++++++++++++++---
drivers/gpu/drm/i915/gt/selftest_rps.h | 1 +
3 files changed, 174 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/selftest_gt_pm.c b/drivers/gpu/drm/i915/gt/selftest_gt_pm.c
index 4b2733967c42..de3eaef40596 100644
--- a/drivers/gpu/drm/i915/gt/selftest_gt_pm.c
+++ b/drivers/gpu/drm/i915/gt/selftest_gt_pm.c
@@ -53,6 +53,7 @@ int intel_gt_pm_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
SUBTEST(live_rc6_manual),
+ SUBTEST(live_rps_control),
SUBTEST(live_rps_frequency),
SUBTEST(live_rps_power),
SUBTEST(live_rps_interrupt),
diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c
index 149a3de86cb9..19fa6a561de3 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.c
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.c
@@ -107,6 +107,172 @@ create_spin_counter(struct intel_engine_cs *engine,
return vma;
}
+static u8 rps_set_check(struct intel_rps *rps, u8 freq)
+{
+ u8 history[64], i;
+ unsigned long end;
+ int sleep;
+
+ mutex_lock(&rps->lock);
+ GEM_BUG_ON(!rps->active);
+ intel_rps_set(rps, freq);
+ GEM_BUG_ON(rps->last_freq != freq);
+ mutex_unlock(&rps->lock);
+
+ i = 0;
+ memset(history, freq, sizeof(history));
+ sleep = 20;
+
+ /* The PCU does not change instantly, but drifts towards the goal? */
+ end = jiffies + msecs_to_jiffies(50);
+ do {
+ u8 act;
+
+ act = read_cagf(rps);
+ if (time_after(jiffies, end))
+ return act;
+
+ /* Target acquired */
+ if (act == freq)
+ return act;
+
+ /* Any change witin the last N samples? */
+ if (!memchr_inv(history, act, sizeof(history)))
+ return act;
+
+ history[i] = act;
+ i = (i + 1) % ARRAY_SIZE(history);
+
+ usleep_range(sleep, 2 * sleep);
+ sleep *= 2;
+ if (sleep > 1000)
+ sleep = 1000;
+ } while (1);
+}
+
+int live_rps_control(void *arg)
+{
+ struct intel_gt *gt = arg;
+ struct intel_rps *rps = >->rps;
+ void (*saved_work)(struct work_struct *wrk);
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ struct igt_spinner spin;
+ int err = 0;
+
+ /*
+ * Check that the actual frequency matches our requested frequency,
+ * to verify our control mechanism. We have to be careful that the
+ * PCU may throttle the GPU in which case the actual frequency used
+ * will be lowered than requested.
+ */
+
+ if (!rps->enabled || rps->max_freq <= rps->min_freq)
+ return 0;
+
+ if (IS_CHERRYVIEW(gt->i915)) /* XXX fragile PCU */
+ return 0;
+
+ if (igt_spinner_init(&spin, gt))
+ return -ENOMEM;
+
+ intel_gt_pm_wait_for_idle(gt);
+ saved_work = rps->work.func;
+ rps->work.func = dummy_rps_work;
+
+ intel_gt_pm_get(gt);
+ for_each_engine(engine, gt, id) {
+ struct i915_request *rq;
+ ktime_t min_dt, max_dt;
+ int act, f, limit;
+ int min, max;
+
+ if (!intel_engine_can_store_dword(engine))
+ continue;
+
+ rq = igt_spinner_create_request(&spin,
+ engine->kernel_context,
+ MI_NOOP);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ break;
+ }
+
+ i915_request_add(rq);
+
+ if (!igt_wait_for_spinner(&spin, rq)) {
+ pr_err("%s: RPS spinner did not start\n",
+ engine->name);
+ igt_spinner_end(&spin);
+ intel_gt_set_wedged(engine->gt);
+ err = -EIO;
+ break;
+ }
+
+ if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
+ pr_err("%s: could not set minimum frequency [%x], only %x!\n",
+ engine->name, rps->min_freq, read_cagf(rps));
+ igt_spinner_end(&spin);
+ err = -EINVAL;
+ break;
+ }
+
+ for (f = rps->min_freq + 1; f < rps->max_freq; f++) {
+ act = rps_set_check(rps, f);
+ if (act < f)
+ break;
+ }
+
+ limit = rps_set_check(rps, f);
+
+ if (rps_set_check(rps, rps->min_freq) != rps->min_freq) {
+ pr_err("%s: could not restore minimum frequency [%x], only %x!\n",
+ engine->name, rps->min_freq, read_cagf(rps));
+ igt_spinner_end(&spin);
+ err = -EINVAL;
+ break;
+ }
+
+ max_dt = ktime_get();
+ max = rps_set_check(rps, limit);
+ max_dt = ktime_sub(ktime_get(), max_dt);
+
+ min_dt = ktime_get();
+ min = rps_set_check(rps, rps->min_freq);
+ min_dt = ktime_sub(ktime_get(), min_dt);
+
+ igt_spinner_end(&spin);
+
+ pr_info("%s: range:[%x:%uMHz, %x:%uMHz] actual:[ %x:%uMHz, %x:%uMHz], %x:%x response %lluns:%lluns\n",
+ engine->name,
+ rps->min_freq, intel_gpu_freq(rps, rps->min_freq),
+ rps->max_freq, intel_gpu_freq(rps, rps->max_freq),
+ act, intel_gpu_freq(rps, act),
+ limit, intel_gpu_freq(rps, limit),
+ min, max, ktime_to_ns(min_dt), ktime_to_ns(max_dt));
+
+ if (limit == rps->min_freq) {
+ pr_err("%s: GPU throttled to minimum!\n",
+ engine->name);
+ err = -ENODEV;
+ break;
+ }
+
+ if (igt_flush_test(gt->i915)) {
+ err = -EIO;
+ break;
+ }
+ }
+ intel_gt_pm_put(gt);
+
+ igt_spinner_fini(&spin);
+
+ intel_gt_pm_wait_for_idle(gt);
+ rps->work.func = saved_work;
+
+ return err;
+}
+
static u64 __measure_frequency(u32 *cntr, int duration_ms)
{
u64 dc, dt;
@@ -125,16 +291,10 @@ static u64 measure_frequency_at(struct intel_rps *rps, u32 *cntr, int *freq)
u64 x[5];
int i;
- mutex_lock(&rps->lock);
- GEM_BUG_ON(!rps->active);
- intel_rps_set(rps, *freq);
- mutex_unlock(&rps->lock);
-
- msleep(20); /* more than enough time to stabilise! */
-
+ *freq = rps_set_check(rps, *freq);
for (i = 0; i < 5; i++)
x[i] = __measure_frequency(cntr, 2);
- *freq = read_cagf(rps);
+ *freq = (*freq + read_cagf(rps)) / 2;
/* A simple triangle filter for better result stability */
sort(x, 5, sizeof(*x), cmp_u64, NULL);
@@ -279,10 +439,7 @@ static int __rps_up_interrupt(struct intel_rps *rps,
if (!intel_engine_can_store_dword(engine))
return 0;
- mutex_lock(&rps->lock);
- GEM_BUG_ON(!rps->active);
- intel_rps_set(rps, rps->min_freq);
- mutex_unlock(&rps->lock);
+ rps_set_check(rps, rps->min_freq);
rq = igt_spinner_create_request(spin, engine->kernel_context, MI_NOOP);
if (IS_ERR(rq))
@@ -354,10 +511,7 @@ static int __rps_down_interrupt(struct intel_rps *rps,
struct intel_uncore *uncore = engine->uncore;
u32 timeout;
- mutex_lock(&rps->lock);
- GEM_BUG_ON(!rps->active);
- intel_rps_set(rps, rps->max_freq);
- mutex_unlock(&rps->lock);
+ rps_set_check(rps, rps->max_freq);
if (!(rps->pm_events & GEN6_PM_RP_DOWN_THRESHOLD)) {
pr_err("%s: RPS did not register DOWN interrupt\n",
@@ -490,16 +644,10 @@ static u64 measure_power_at(struct intel_rps *rps, int *freq)
u64 x[5];
int i;
- mutex_lock(&rps->lock);
- GEM_BUG_ON(!rps->active);
- intel_rps_set(rps, *freq);
- mutex_unlock(&rps->lock);
-
- msleep(20); /* more than enough time to stabilise! */
-
+ *freq = rps_set_check(rps, *freq);
for (i = 0; i < 5; i++)
x[i] = __measure_power(5);
- *freq = read_cagf(rps);
+ *freq = (*freq + read_cagf(rps)) / 2;
/* A simple triangle filter for better result stability */
sort(x, 5, sizeof(*x), cmp_u64, NULL);
diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.h b/drivers/gpu/drm/i915/gt/selftest_rps.h
index 07c2bddf8899..be0bf8e3f639 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.h
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.h
@@ -6,6 +6,7 @@
#ifndef SELFTEST_RPS_H
#define SELFTEST_RPS_H
+int live_rps_control(void *arg);
int live_rps_frequency(void *arg);
int live_rps_interrupt(void *arg);
int live_rps_power(void *arg);
--
2.20.1
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