drm/i915: Show per-engine default property values in sysfs

By providing the default values configured into the kernel via sysfs, it
is much more convenient for userspace to restore those sane defaults, or
at least know what are considered good baseline. This is useful, for
example, to cleanup after any failed userspace prior to commencing new
jobs.

/sys/class/drm/card0/engine/rcs0/
├── capabilities
├── class
├── .defaults
│   ├── heartbeat_interval_ms
│   ├── max_busywait_duration_ns
│   ├── preempt_timeout_ms
│   ├── stop_timeout_ms
│   └── timeslice_duration_ms
├── heartbeat_interval_ms
├── instance
├── known_capabilities
├── max_busywait_duration_ns
├── mmio_base
├── name
├── preempt_timeout_ms
├── stop_timeout_ms
└── timeslice_duration_ms

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200514062905.28668-1-chris@chris-wilson.co.uk

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index c113b7805e65..c39db7e249e2 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -565,7 +565,7 @@ struct intel_engine_cs {
 		unsigned long preempt_timeout_ms;
 		unsigned long stop_timeout_ms;
 		unsigned long timeslice_duration_ms;
-	} props;
+	} props, defaults;
 };
 
 static inline bool