[Intel-gfx] [PATCH] drm/i915/gt: Force the GT reset on shutdown

[Chris Wilson]

Before we return control to the system, and letting it reuse all the
pages being accessed by HW, we must disable the HW. At the moment, we
dare not reset the GPU if it will clobber the display, but once we know
the display has been disabled, we can proceed with the reset as we
shutdown the module. We know the next user must reinitialise the HW for
their purpose.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/489
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: stable at kernel.org
---
 drivers/gpu/drm/i915/gt/intel_gt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index f069551e412f..4eb81e54ffed 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -628,6 +628,12 @@ void intel_gt_driver_release(struct intel_gt *gt)
 
 void intel_gt_driver_late_release(struct intel_gt *gt)
 {
+	intel_wakeref_t wakeref;
+
+	/* Scrub all HW state upon release */
+	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
+		__intel_gt_reset(gt, ALL_ENGINES);
+
 	/* We need to wait for inflight RCU frees to release their grip */
 	rcu_barrier();
 
-- 
2.20.1