Now that we have offline error capture and can reset an engine from
inside an atomic context while also preserving the GPU state for
post-mortem analysis, it is time to handle error interrupts thrown by
the command parser.
This provides a much, much faster mechanism for us to detect known
problems than using heartbeats/hangchecks, and also provides a mechanism
for when those are disabled. However, it is limited to problems the HW
can detect in the CS and so not a complete solution for detecting lockups.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128204318.4182039-2-chris@chris-wilson.co.uk
The design of our interrupt handlers is that we ack the receipt of the
interrupt first, inside the critical section where the master interrupt
control is off and other cpus cannot start processing the next
interrupt; and then process the interrupt events afterwards. However,
Icelake introduced a whole new set of banked GT_IIR that are inherently
serialised and slow to retrieve the IIR and must be processed within the
critical section. We can still push our breadcrumbs out of this critical
section by using our irq_worker. On bdw+, this should not make too much
of a difference as we only slightly defer the breadcrumbs, but on icl+
this should make a big difference to our throughput of interrupts from
concurrently executing engines.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191127115813.3345823-1-chris@chris-wilson.co.uk
