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From:   Robert Beckett <bob.beckett@collabora.com>
To:     dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     kernel@collabora.com, Robert Beckett <bob.beckett@collabora.com>,
        Matthew Auld <matthew.auld@intel.com>,
        =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= 
        <thomas.hellstrom@linux.intel.com>, linux-kernel@vger.kernel.org
Subject: [PATCH v10 09/11] drm/i915/selftest: don't attempt engine reset of guc submission engines
Date:   Thu,  7 Jul 2022 20:02:27 +0000
Message-Id: <20220707200230.1657555-10-bob.beckett@collabora.com>
In-Reply-To: <20220707200230.1657555-1-bob.beckett@collabora.com>
References: <20220707200230.1657555-1-bob.beckett@collabora.com>
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igt_reset_engines_stolen tries to reset engines without checking if it
is possible.
Engines using GuC submission are not able to be reset from the host.

In this scenario, the reset exits early, then on the next iteration of
the each engine loop, the async teardown of the spinner request
context's ring occurs while the next engine is under test.

This is seen as a stolen memory corruption as the ring buffer was busy
initially, but free during the confirmation check and had been poisoned
during cleanup.

Fix this by not testing GuC submission using engines.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/gt/selftest_reset.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_reset.c b/drivers/gpu/drm/i915/gt/selftest_reset.c
index 37c38bdd5f47..55f3b34e5f6e 100644
--- a/drivers/gpu/drm/i915/gt/selftest_reset.c
+++ b/drivers/gpu/drm/i915/gt/selftest_reset.c
@@ -194,6 +194,8 @@ static int igt_reset_engines_stolen(void *arg)
 		return 0;
 
 	for_each_engine(engine, gt, id) {
+		if (intel_engine_uses_guc(engine))
+			continue;
 		err = __igt_reset_stolen(gt, engine->mask, engine->name);
 		if (err)
 			return err;
-- 
2.25.1