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From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: [Intel-gfx] [PATCH] drm/i915/gt: Check we are the Ironlake IPS provider before deregistering
Date: Tue, 10 Dec 2019 15:36:20 +0000	[thread overview]
Message-ID: <20191210153620.3929372-1-chris@chris-wilson.co.uk> (raw)

Check that we own the global pointer before deregistering.

Reported-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_rps.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
index 08a38a3b90b0..fd01e4100fc1 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -1715,6 +1715,7 @@ void intel_rps_driver_register(struct intel_rps *rps)
 	 * set up, to avoid intel-ips sneaking in and reading bogus values.
 	 */
 	if (IS_GEN(gt->i915, 5)) {
+		GEM_BUG_ON(ips_mchdev);
 		rcu_assign_pointer(ips_mchdev, gt->i915);
 		ips_ping_for_i915_load();
 	}
@@ -1722,7 +1723,8 @@ void intel_rps_driver_register(struct intel_rps *rps)
 
 void intel_rps_driver_unregister(struct intel_rps *rps)
 {
-	rcu_assign_pointer(ips_mchdev, NULL);
+	if (ips_mchdev == rps_to_i915(rps))
+		rcu_assign_pointer(ips_mchdev, NULL);
 }
 
 static struct drm_i915_private *mchdev_get(void)
-- 
2.24.0

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             reply	other threads:[~2019-12-10 15:36 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-10 15:36 Chris Wilson [this message]
2019-12-10 17:09 ` [Intel-gfx] [PATCH] drm/i915/gt: Check we are the Ironlake IPS provider before deregistering Venkata Sandeep Dhanalakota
2019-12-11  1:56 ` [Intel-gfx] ✗ Fi.CI.SPARSE: warning for " Patchwork
2019-12-11  2:17 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2019-12-11  7:49 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork

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