drm/i915/gt: Force the GT reset on shutdown

commit 7c4541a37bbbf83c0f16f779e85eb61d9348ed29 upstream.

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@chris-wilson.co.uk>
Cc: stable@kernel.org
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200525151459.12083-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index d09f7596cb98b4fbb3e3d94edf54fb2740b430e4..1c2f7a5b1e94af3be0d3a58c89f9c6643a37d2c8 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -656,6 +656,11 @@ void intel_gt_driver_unregister(struct intel_gt *gt)
 void intel_gt_driver_release(struct intel_gt *gt)
 {
        struct i915_address_space *vm;
+       intel_wakeref_t wakeref;
+
+       /* Scrub all HW state upon release */
+       with_intel_runtime_pm(gt->uncore->rpm, wakeref)
+               __intel_gt_reset(gt, ALL_ENGINES);
 
        vm = fetch_and_zero(&gt->vm);
        if (vm) /* FIXME being called twice on error paths :( */