Commit aa7b93eb authored by Chris Wilson's avatar Chris Wilson Committed by Andrzej Hajda
Browse files

drm/i915/gt: Hold a wakeref for the active VM 



There may be a disconnect between the GT used by the engine and the GT
used for the VM, requiring us to hold a wakeref on both while the GPU is
active with this request.

v2: added explanation to __queue_and_release_pm

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
[ahajda: removed not-yet-upstremed wakeref tracking bits]
Signed-off-by: default avatarAndrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230330-hold_wakeref_for_active_vm-v2-1-724d201499c2@intel.com
parent a915450e

drivers/gpu/drm/i915/gt/intel_context.h

+11 −4
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include "i915_drv.h"

#include "intel_context_types.h"

#include "intel_engine_types.h"

#include "intel_gt_pm.h"

#include "intel_ring_types.h"

#include "intel_timeline_types.h"

#include "i915_trace.h"
@@ -207,8 +208,11 @@ void intel_context_exit_engine(struct intel_context *ce); 
static inline void intel_context_enter(struct intel_context *ce)

{

	lockdep_assert_held(&ce->timeline->mutex);

	if (!ce->active_count++)

	if (ce->active_count++)

		return;



	ce->ops->enter(ce);

	intel_gt_pm_get(ce->vm->gt);

}



static inline void intel_context_mark_active(struct intel_context *ce)
@@ -222,7 +226,10 @@ static inline void intel_context_exit(struct intel_context *ce) 
{

	lockdep_assert_held(&ce->timeline->mutex);

	GEM_BUG_ON(!ce->active_count);

	if (!--ce->active_count)

	if (--ce->active_count)

		return;



	intel_gt_pm_put_async(ce->vm->gt);

	ce->ops->exit(ce);

}

drivers/gpu/drm/i915/gt/intel_engine_pm.c

+9 −0
Original line number Diff line number Diff line
@@ -114,6 +114,15 @@ __queue_and_release_pm(struct i915_request *rq, 


	ENGINE_TRACE(engine, "parking\n");



	/*

	 * Open coded one half of intel_context_enter, which we have to omit

	 * here (see the large comment below) and because the other part must

	 * not be called due constructing directly with __i915_request_create

	 * which increments active count via intel_context_mark_active.

	 */

	GEM_BUG_ON(rq->context->active_count != 1);

	__intel_gt_pm_get(engine->gt);



	/*

	 * We have to serialise all potential retirement paths with our

	 * submission, as we don't want to underflow either the