From 336d6d0cf1288b79b6397a03741f894418dc2157 Mon Sep 17 00:00:00 2001
From: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Date: Wed, 8 Dec 2021 10:33:13 -0800
Subject: drm/i915/pmu: Wait longer for busyness data to be available from GuC
Git-commit: 0b64e2e43ddeb010d3f2a45f978e6cb919cd0895
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
live_engine_busy_stats waits for busyness to start ticking before
sampling busyness for the test sample duration. The wait accesses an
MMIO register and the uncore call to read it takes up to 3 ms in the
worst case. This can result in the wait timing out since the MMIO read
itself consumes up the timeout of 500us. Increase the timeout to a
larger value of 10ms to account for the MMIO read time.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4536
Fixes: 77cdd054dd2c ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211208183313.13126-1-umesh.nerlige.ramappa@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gt/selftest_engine_pm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
index 75f6efc9882f..8af261831470 100644
--- a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
@@ -229,7 +229,7 @@ static int __spin_until_busier(struct intel_engine_cs *engine, ktime_t busyness)
start = ktime_get();
while (intel_engine_get_busy_time(engine, &unused) == busyness) {
dt = ktime_get() - start;
- if (dt > 500000) {
+ if (dt > 10000000) {
pr_err("active wait timed out %lld\n", dt);
ENGINE_TRACE(engine, "active wait time out %lld\n", dt);
return -ETIME;
--
2.38.1