From: jsg <jsg@openbsd.org>
Date: Tue, 6 Feb 2024 03:53:15 +0000 (+0000)
Subject: drm/amdkfd: Fix lock dependency warning with srcu
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=6ba23f6e8a4aedef84ddc2226579d8bc979dc50c;p=openbsd

drm/amdkfd: Fix lock dependency warning with srcu

From Philip Yang
752312f6a79440086ac0f9b08d7776870037323c in linux-6.6.y/6.6.16
2a9de42e8d3c82c6990d226198602be44f43f340 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/amdkfd/kfd_svm.c b/sys/dev/pci/drm/amd/amdkfd/kfd_svm.c
index a4c911fa167..b51224a85a3 100644
--- a/sys/dev/pci/drm/amd/amdkfd/kfd_svm.c
+++ b/sys/dev/pci/drm/amd/amdkfd/kfd_svm.c
@@ -2343,8 +2343,10 @@ retry:
 		mutex_unlock(&svms->lock);
 		mmap_write_unlock(mm);
 
-		/* Pairs with mmget in svm_range_add_list_work */
-		mmput(mm);
+		/* Pairs with mmget in svm_range_add_list_work. If dropping the
+		 * last mm refcount, schedule release work to avoid circular locking
+		 */
+		mmput_async(mm);
 
 		spin_lock(&svms->deferred_list_lock);
 	}