drm/i915/gt: Ignore irq enabling on the virtual engines

BugLink: https://bugs.launchpad.net/bugs/1888560
commit 858f1299fd6f7518ddef19ddd304c8398ac79fa5 upstream.

We do not use the virtual engines for interrupts (they have physical
components), but we do use them to decouple the fence signaling during
submission. Currently, when we submit a completed request, we try to
enable the interrupt handler for the virtual engine, but we never disarm
it. A quick fix is then to mark the irq as enabled, and it will then
remain enabled -- and this prevents us from waking the device and never
letting it sleep again.

Fixes: f8db4d051b5e ("drm/i915: Initialise breadcrumb lists on the virtual engine")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200711203236.12330-1-chris@chris-wilson.co.uk
(cherry picked from commit 4fe6abb8f51355224808ab02a9febf65d184c40b)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 58916adadbead975fc132c430a55859948e697ea..1ac06842e349da0b162965ba01a52055ab468aa9 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3766,6 +3766,7 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
        intel_engine_init_active(&ve->base, ENGINE_VIRTUAL);
 
        intel_engine_init_execlists(&ve->base);
+       ve->base.breadcrumbs.irq_armed = true; /* fake HW, used for irq_work */
 
        ve->base.cops = &virtual_context_ops;
        ve->base.request_alloc = execlists_request_alloc;