Hi,
This series of two patches fixes the issue introduced in cf586021642d80 ("drm/i915/gt: Pipelined page migration") where, as reported by Matt, in a chain of requests an error is reported only if happens in the last request.
However Chris noticed that without ensuring exclusivity in the locking we might end up in some deadlock. That's why patch 1 throttles for the ringspace in order to make sure that no one is holding it.
Version 1 of this patch has been reviewed by matt and this version is adding Chris exclusive locking.
Thanks Chris for this work.
Andi
Changelog ========= v3 -> v4 - In v3 the timeline was being locked, but I forgot that also request_create() and request_add() are locking the timeline as well. The former does the locking, the latter does the unlocking. In order to avoid this extra lock/unlock, we need the "_locked" version of the said functions.
v2 -> v3 - Really lock the timeline before generating all the requests until the last.
v1 -> v2 - Add patch 1 for ensuring exclusive locking of the timeline - Reword git commit of patch 2.
Andi Shyti (4): drm/i915/gt: Add intel_context_timeline_is_locked helper drm/i915: Create the locked version of the request create drm/i915: Create the locked version of the request add drm/i915/gt: Make sure that errors are propagated through request chains
Chris Wilson (1): drm/i915: Throttle for ringspace prior to taking the timeline mutex
drivers/gpu/drm/i915/gt/intel_context.c | 41 +++++++++++++++++++ drivers/gpu/drm/i915/gt/intel_context.h | 8 ++++ drivers/gpu/drm/i915/gt/intel_migrate.c | 41 ++++++++++++++----- drivers/gpu/drm/i915/i915_request.c | 54 ++++++++++++++++++------- drivers/gpu/drm/i915/i915_request.h | 3 ++ 5 files changed, 122 insertions(+), 25 deletions(-)