From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 19 May 2020 06:31:13 +0000 (+0100)
Subject: drm/i915/selftests: Change priority overflow detection
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ad6586850b6d718b1245bad6702028c1c773cfb9;p=linux.git

drm/i915/selftests: Change priority overflow detection

Check for integer overflow in the priority chain, rather than against a
type-constricted max-priority check.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200519063123.20673-2-chris@chris-wilson.co.uk
---

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 94854a467e666..3e042fa4b94bc 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -2735,12 +2735,12 @@ static int live_preempt_gang(void *arg)
 			/* Submit each spinner at increasing priority */
 			engine->schedule(rq, &attr);
 
+			if (prio < attr.priority)
+				break;
+
 			if (prio <= I915_PRIORITY_MAX)
 				continue;
 
-			if (prio > (INT_MAX >> I915_USER_PRIORITY_SHIFT))
-				break;
-
 			if (__igt_timeout(end_time, NULL))
 				break;
 		} while (1);