To optimize some task deferring it until runtime resume unless someone
holds a runtime PM reference (because in this case the task can be done
w/o the overhead of runtime resume), we have to use the runtime PM
get-if-active logic: If the runtime PM usage count is 0 (and so
get-if-in-use would return false) the runtime suspend handler is not
necessarily called yet (it could be just pending), so the device is not
necessarily powered down, and so the runtime resume handler is not
guaranteed to be called.
The fence revocation depends on the above deferral, so add a
get-if-active helper and use it during fence revocation.
v2:
- Add code comment explaining the fence reg programming deferral logic
to i915_vma_revoke_fence(). (Chris)
- Add Cc: stable and Fixes: tags. (Chris)
- Fix the function docbook comment.
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.12+
Fixes: 181df2d458 ("drm/i915: Take rpm wakelock for releasing the fence on unbind")
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322204223.919936-1-imre.deak@intel.com
If we want to reuse a fence that is in active use by the GPU, we have to
wait an uncertain amount of time, but if we reuse an inactive fence, we
can change it right away. Loop through the list of available fences
twice, ignoring any active fences on the first pass.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201223122051.4624-1-chris@chris-wilson.co.uk
If we must revoke the fence because the VMA is no longer present, or
because the fence no longer applies, ensure that we do and convert it
into an error if we try but cannot.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401210104.15907-3-chris@chris-wilson.co.uk
Only GPU activity via the GGTT fence is asynchronous, we know that we
control the CPU access directly, so we only need to wait for the GPU to
stop using the fence before we relinquish it.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401210104.15907-1-chris@chris-wilson.co.uk
Apparently we do try and attach a fence to an invalid vma (during
execbuf) so we cannot simply assert it never happens and report EINVAL
instead.
Fixes: dec9cf9ee8 ("drm/i915/gt: Pull restoration of GGTT fences underneath the GT")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200316205450.15843-1-chris@chris-wilson.co.uk
