From e40c00b080906bf8ab50300cc75690608a4815f9 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 10 Dec 2019 15:36:20 +0000
Subject: drm/i915/gt: Check we are the Ironlake IPS provider before
Git-commit: c0168a3ee6208e72050f47473d9b63fa248ca582
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
deregistering
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>
Reviewed-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191210153620.3929372-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
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)
--
2.28.0