[Intel-gfx] [PATCH] drm/i915/gt: Fix up clock frequency
Chris Wilson
chris at chris-wilson.co.uk
Mon Apr 27 12:02:07 UTC 2020
The bspec lists both the clock frequency and the effective interval. The
interval corresponds to observed behaviour, so adjust the frequency to
match.
v2: Mika rightfully asked if we could measure the clock frequency from a
selftest.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
.../gpu/drm/i915/gt/intel_gt_clock_utils.c | 12 +-
drivers/gpu/drm/i915/gt/selftest_gt_pm.c | 1 +
drivers/gpu/drm/i915/gt/selftest_rps.c | 125 ++++++++++++++++++
drivers/gpu/drm/i915/gt/selftest_rps.h | 1 +
4 files changed, 133 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
index 852a7d731b3b..999079686846 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
@@ -7,9 +7,9 @@
#include "intel_gt.h"
#include "intel_gt_clock_utils.h"
+#define MHZ_12 12000000 /* 12MHz (24MHz/2), 83.333ns */
+#define MHZ_12_5 12500000 /* 12.5MHz (25MHz/2), 80ns */
#define MHZ_19_2 19200000 /* 19.2MHz, 52.083ns */
-#define MHZ_24 24000000 /* 24MHz, 83.333ns */
-#define MHZ_25 25000000 /* 25MHz, 80ns */
static u32 read_clock_frequency(const struct intel_gt *gt)
{
@@ -21,19 +21,19 @@ static u32 read_clock_frequency(const struct intel_gt *gt)
config >>= GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
switch (config) {
- case 0: return MHZ_24;
+ case 0: return MHZ_12;
case 1:
case 2: return MHZ_19_2;
default:
- case 3: return MHZ_25;
+ case 3: return MHZ_12_5;
}
} else if (INTEL_GEN(gt->i915) >= 9) {
if (IS_GEN9_LP(gt->i915))
return MHZ_19_2;
else
- return MHZ_24;
+ return MHZ_12;
} else {
- return MHZ_25;
+ return MHZ_12_5;
}
}
diff --git a/drivers/gpu/drm/i915/gt/selftest_gt_pm.c b/drivers/gpu/drm/i915/gt/selftest_gt_pm.c
index e02fdec58826..242181a5214c 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_clock_interval),
SUBTEST(live_rps_control),
SUBTEST(live_rps_frequency_cs),
SUBTEST(live_rps_frequency_srm),
diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c
index e13cbcb82825..fe92c55572c1 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.c
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.c
@@ -208,6 +208,131 @@ static void show_pstate_limits(struct intel_rps *rps)
}
}
+int live_rps_clock_interval(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;
+
+ if (!rps->enabled)
+ return 0;
+
+ intel_gt_check_clock_frequency(gt);
+
+ 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);
+ intel_rps_disable(>->rps);
+
+ for_each_engine(engine, gt, id) {
+ unsigned long saved_heartbeat;
+ struct i915_request *rq;
+ u32 cycles, expected;
+ ktime_t dt;
+ u64 time;
+
+ if (!intel_engine_can_store_dword(engine))
+ continue;
+
+ saved_heartbeat = engine_heartbeat_disable(engine);
+
+ 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);
+ engine_heartbeat_enable(engine, saved_heartbeat);
+ intel_gt_set_wedged(engine->gt);
+ err = -EIO;
+ break;
+ }
+
+ intel_uncore_write(gt->uncore, GEN6_RP_CUR_UP_EI, 0);
+
+ /* Set the evaluation interval to infinity! */
+ intel_uncore_write(gt->uncore,
+ GEN6_RP_UP_EI, 0xffffffff);
+ intel_uncore_write(gt->uncore,
+ GEN6_RP_UP_THRESHOLD, 0xffffffff);
+
+ intel_uncore_write(gt->uncore, GEN6_RP_CONTROL,
+ GEN6_RP_ENABLE | GEN6_RP_UP_BUSY_AVG);
+
+ if (wait_for(intel_uncore_read(gt->uncore, GEN6_RP_CUR_UP_EI),
+ 10)) {
+ pr_err("%s: rps evalution interval not ticking\n",
+ engine->name);
+ igt_spinner_end(&spin);
+ engine_heartbeat_enable(engine, saved_heartbeat);
+ err = -ENODEV;
+ break;
+ }
+
+ dt = ktime_get();
+ cycles = -intel_uncore_read(gt->uncore, GEN6_RP_CUR_UP_EI);
+ usleep_range(1000, 2000);
+ dt = ktime_sub(ktime_get(), dt);
+ cycles += intel_uncore_read(gt->uncore, GEN6_RP_CUR_UP_EI);
+
+ intel_uncore_write(gt->uncore, GEN6_RP_CONTROL, 0);
+
+ igt_spinner_end(&spin);
+ engine_heartbeat_enable(engine, saved_heartbeat);
+
+ time = intel_gt_pm_interval_to_ns(gt, cycles);
+ expected = intel_gt_ns_to_pm_interval(gt, ktime_to_ns(dt));
+ pr_info("%s: rps counted %d C0 cycles [%lldns] in %lldns [%d cycles], using GT clock frequency of %uKHz\n",
+ engine->name, cycles, time, ktime_to_ns(dt), expected,
+ gt->clock_frequency / 1000);
+
+ if (10 * time < 9 * ktime_to_ns(dt) ||
+ 10 * time > 11 * ktime_to_ns(dt)) {
+ pr_err("%s: rps clock time does not match walltime!\n",
+ engine->name);
+ err = -EINVAL;
+ }
+
+ if (10 * expected < 9 * cycles || 10 * expected > 11 * cycles) {
+ pr_err("%s: walltime does not match rps clock ticks!\n",
+ engine->name);
+ err = -EINVAL;
+ }
+
+ if (igt_flush_test(gt->i915))
+ err = -EIO;
+
+ break; /* once is enough */
+ }
+
+ intel_rps_enable(>->rps);
+ intel_gt_pm_put(gt);
+
+ igt_spinner_fini(&spin);
+
+ intel_gt_pm_wait_for_idle(gt);
+ rps->work.func = saved_work;
+
+ return err;
+}
+
int live_rps_control(void *arg)
{
struct intel_gt *gt = arg;
diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.h b/drivers/gpu/drm/i915/gt/selftest_rps.h
index 76c4b19553e6..6e82a631cfa1 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.h
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.h
@@ -7,6 +7,7 @@
#define SELFTEST_RPS_H
int live_rps_control(void *arg);
+int live_rps_clock_interval(void *arg);
int live_rps_frequency_cs(void *arg);
int live_rps_frequency_srm(void *arg);
int live_rps_power(void *arg);
--
2.20.1
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