msm: ipa: fix delete dependency race condition

IPA RM dependencies are added both by kernel drivers and by
userspace application (IPACM), depending on the use case.
On rare condition, a race is possible between adding the dependency
and deleting it, which results in a bad state of the dependency graph.
This change makes sure that dependency is deleted only if it was added
by the same entity.

CRs-Fixed: 1027773
Change-Id: I9253469887b8913f6f2c513a6c7043ed60400b8a
Acked-by Ady Abraham <adya@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>

10 files changed, 253 insertions, 75 deletions

diff --git a/drivers/platform/msm/ipa/ipa_rm.c b/drivers/platform/msm/ipa/ipa_rm.c
index d0bde0e9654b..a9813311f156 100644
--- a/drivers/platform/msm/ipa/ipa_rm.c
+++ b/drivers/platform/msm/ipa/ipa_rm.c
@@ -172,19 +172,9 @@ bail:
 }
 EXPORT_SYMBOL(ipa_rm_delete_resource);
 
-/**
- * ipa_rm_add_dependency() - create dependency
- *					between 2 resources
- * @resource_name: name of dependent resource
- * @depends_on_name: name of its dependency
- *
- * Returns: 0 on success, negative on failure
- *
- * Side effects: IPA_RM_RESORCE_GRANTED could be generated
- * in case client registered with IPA RM
- */
-int ipa_rm_add_dependency(enum ipa_rm_resource_name resource_name,
-			enum ipa_rm_resource_name depends_on_name)
+static int _ipa_rm_add_dependency(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name,
+			bool userspace_dep)
 {
 	unsigned long flags;
 	int result;
@@ -200,29 +190,53 @@ int ipa_rm_add_dependency(enum ipa_rm_resource_name resource_name,
 	result = ipa_rm_dep_graph_add_dependency(
 						ipa_rm_ctx->dep_graph,
 						resource_name,
-						depends_on_name);
+						depends_on_name,
+						userspace_dep);
 	spin_unlock_irqrestore(&ipa_rm_ctx->ipa_rm_lock, flags);
 	IPA_RM_DBG("EXIT with %d\n", result);
 
 	return result;
 }
+
+/**
+ * ipa_rm_add_dependency() - create dependency between 2 resources
+ * @resource_name: name of dependent resource
+ * @depends_on_name: name of its dependency
+ *
+ * Returns: 0 on success, negative on failure
+ *
+ * Side effects: IPA_RM_RESORCE_GRANTED could be generated
+ * in case client registered with IPA RM
+ */
+int ipa_rm_add_dependency(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_add_dependency(resource_name, depends_on_name, false);
+}
 EXPORT_SYMBOL(ipa_rm_add_dependency);
 
 /**
- * ipa_rm_add_dependency_sync() - Create a dependency between 2 resources
- * in a synchronized fashion. In case a producer resource is in GRANTED state
- * and the newly added consumer resource is in RELEASED state, the consumer
- * entity will be requested and the function will block until the consumer
- * is granted.
+ * ipa_rm_add_dependency_from_ioctl() - create dependency between 2 resources
  * @resource_name: name of dependent resource
  * @depends_on_name: name of its dependency
  *
+ * This function is expected to be called from IOCTL and the dependency will be
+ * marked as is was added by the userspace.
+ *
  * Returns: 0 on success, negative on failure
  *
- * Side effects: May block. See documentation above.
+ * Side effects: IPA_RM_RESORCE_GRANTED could be generated
+ * in case client registered with IPA RM
  */
-int ipa_rm_add_dependency_sync(enum ipa_rm_resource_name resource_name,
-		enum ipa_rm_resource_name depends_on_name)
+int ipa_rm_add_dependency_from_ioctl(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_add_dependency(resource_name, depends_on_name, true);
+}
+
+static int _ipa_rm_add_dependency_sync(enum ipa_rm_resource_name resource_name,
+		enum ipa_rm_resource_name depends_on_name,
+		bool userspsace_dep)
 {
 	int result;
 	struct ipa_rm_resource *consumer;
@@ -240,7 +254,8 @@ int ipa_rm_add_dependency_sync(enum ipa_rm_resource_name resource_name,
 	result = ipa_rm_dep_graph_add_dependency(
 						ipa_rm_ctx->dep_graph,
 						resource_name,
-						depends_on_name);
+						depends_on_name,
+						userspsace_dep);
 	spin_unlock_irqrestore(&ipa_rm_ctx->ipa_rm_lock, flags);
 	if (result == -EINPROGRESS) {
 		ipa_rm_dep_graph_get_resource(ipa_rm_ctx->dep_graph,
@@ -268,21 +283,54 @@ int ipa_rm_add_dependency_sync(enum ipa_rm_resource_name resource_name,
 
 	return result;
 }
+/**
+ * ipa_rm_add_dependency_sync() - Create a dependency between 2 resources
+ * in a synchronized fashion. In case a producer resource is in GRANTED state
+ * and the newly added consumer resource is in RELEASED state, the consumer
+ * entity will be requested and the function will block until the consumer
+ * is granted.
+ * @resource_name: name of dependent resource
+ * @depends_on_name: name of its dependency
+ *
+ * This function is expected to be called from IOCTL and the dependency will be
+ * marked as is was added by the userspace.
+ *
+ * Returns: 0 on success, negative on failure
+ *
+ * Side effects: May block. See documentation above.
+ */
+int ipa_rm_add_dependency_sync(enum ipa_rm_resource_name resource_name,
+		enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_add_dependency_sync(resource_name, depends_on_name,
+		false);
+}
 EXPORT_SYMBOL(ipa_rm_add_dependency_sync);
 
 /**
- * ipa_rm_delete_dependency() - create dependency
- *					between 2 resources
+ * ipa_rm_add_dependency_sync_from_ioctl() - Create a dependency between 2
+ * resources in a synchronized fashion. In case a producer resource is in
+ * GRANTED state and the newly added consumer resource is in RELEASED state,
+ * the consumer entity will be requested and the function will block until
+ * the consumer is granted.
  * @resource_name: name of dependent resource
  * @depends_on_name: name of its dependency
  *
  * Returns: 0 on success, negative on failure
  *
- * Side effects: IPA_RM_RESORCE_GRANTED could be generated
- * in case client registered with IPA RM
+ * Side effects: May block. See documentation above.
  */
-int ipa_rm_delete_dependency(enum ipa_rm_resource_name resource_name,
-			enum ipa_rm_resource_name depends_on_name)
+int ipa_rm_add_dependency_sync_from_ioctl(
+	enum ipa_rm_resource_name resource_name,
+	enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_add_dependency_sync(resource_name, depends_on_name,
+		true);
+}
+
+static int _ipa_rm_delete_dependency(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name,
+			bool userspace_dep)
 {
 	unsigned long flags;
 	int result;
@@ -298,15 +346,51 @@ int ipa_rm_delete_dependency(enum ipa_rm_resource_name resource_name,
 	result = ipa_rm_dep_graph_delete_dependency(
 			  ipa_rm_ctx->dep_graph,
 			  resource_name,
-			  depends_on_name);
+			  depends_on_name,
+			  userspace_dep);
 	spin_unlock_irqrestore(&ipa_rm_ctx->ipa_rm_lock, flags);
 	IPA_RM_DBG("EXIT with %d\n", result);
 
 	return result;
 }
+
+/**
+ * ipa_rm_delete_dependency() - delete dependency between 2 resources
+ * @resource_name: name of dependent resource
+ * @depends_on_name: name of its dependency
+ *
+ * Returns: 0 on success, negative on failure
+ *
+ * Side effects: IPA_RM_RESORCE_GRANTED could be generated
+ * in case client registered with IPA RM
+ */
+int ipa_rm_delete_dependency(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_delete_dependency(resource_name, depends_on_name, false);
+}
 EXPORT_SYMBOL(ipa_rm_delete_dependency);
 
 /**
+ * ipa_rm_delete_dependency_fron_ioctl() - delete dependency between 2 resources
+ * @resource_name: name of dependent resource
+ * @depends_on_name: name of its dependency
+ *
+ * This function is expected to be called from IOCTL and the dependency will be
+ * marked as is was added by the userspace.
+ *
+ * Returns: 0 on success, negative on failure
+ *
+ * Side effects: IPA_RM_RESORCE_GRANTED could be generated
+ * in case client registered with IPA RM
+ */
+int ipa_rm_delete_dependency_from_ioctl(enum ipa_rm_resource_name resource_name,
+			enum ipa_rm_resource_name depends_on_name)
+{
+	return _ipa_rm_delete_dependency(resource_name, depends_on_name, true);
+}
+
+/**
  * ipa_rm_request_resource() - request resource
  * @resource_name: [in] name of the requested resource
  *
diff --git a/drivers/platform/msm/ipa/ipa_rm_dependency_graph.c b/drivers/platform/msm/ipa/ipa_rm_dependency_graph.c
index fd437b0c8775..54cad888cb7f 100644
--- a/drivers/platform/msm/ipa/ipa_rm_dependency_graph.c
+++ b/drivers/platform/msm/ipa/ipa_rm_dependency_graph.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -152,12 +152,14 @@ int ipa_rm_dep_graph_remove(struct ipa_rm_dep_graph *graph,
  * @graph: [in] dependency graph
  * @resource_name: [in] resource to add
  * @depends_on_name: [in] resource to add
+ * @userspace_dep: [in] operation requested by userspace ?
  *
  * Returns: 0 on success, negative on failure
  */
 int ipa_rm_dep_graph_add_dependency(struct ipa_rm_dep_graph *graph,
 				    enum ipa_rm_resource_name resource_name,
-				    enum ipa_rm_resource_name depends_on_name)
+				    enum ipa_rm_resource_name depends_on_name,
+				    bool userspace_dep)
 {
 	struct ipa_rm_resource *dependent = NULL;
 	struct ipa_rm_resource *dependency = NULL;
@@ -186,7 +188,8 @@ int ipa_rm_dep_graph_add_dependency(struct ipa_rm_dep_graph *graph,
 		result = -EINVAL;
 		goto bail;
 	}
-	result = ipa_rm_resource_add_dependency(dependent, dependency);
+	result = ipa_rm_resource_add_dependency(dependent, dependency,
+		userspace_dep);
 bail:
 	IPA_RM_DBG("EXIT with %d\n", result);
 
@@ -199,13 +202,15 @@ bail:
  * @graph: [in] dependency graph
  * @resource_name: [in] resource to delete
  * @depends_on_name: [in] resource to delete
+ * @userspace_dep: [in] operation requested by userspace ?
  *
  * Returns: 0 on success, negative on failure
  *
  */
 int ipa_rm_dep_graph_delete_dependency(struct ipa_rm_dep_graph *graph,
 				enum ipa_rm_resource_name resource_name,
-				enum ipa_rm_resource_name depends_on_name)
+				enum ipa_rm_resource_name depends_on_name,
+				bool userspace_dep)
 {
 	struct ipa_rm_resource *dependent = NULL;
 	struct ipa_rm_resource *dependency = NULL;
@@ -237,7 +242,8 @@ int ipa_rm_dep_graph_delete_dependency(struct ipa_rm_dep_graph *graph,
 		goto bail;
 	}
 
-	result = ipa_rm_resource_delete_dependency(dependent, dependency);
+	result = ipa_rm_resource_delete_dependency(dependent, dependency,
+		userspace_dep);
 bail:
 	IPA_RM_DBG("EXIT with %d\n", result);
 
diff --git a/drivers/platform/msm/ipa/ipa_rm_dependency_graph.h b/drivers/platform/msm/ipa/ipa_rm_dependency_graph.h
index b76c6636f873..e322d813e4ea 100644
--- a/drivers/platform/msm/ipa/ipa_rm_dependency_graph.h
+++ b/drivers/platform/msm/ipa/ipa_rm_dependency_graph.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -38,10 +38,12 @@ int ipa_rm_dep_graph_remove(struct ipa_rm_dep_graph *graph,
 
 int ipa_rm_dep_graph_add_dependency(struct ipa_rm_dep_graph *graph,
 				enum ipa_rm_resource_name resource_name,
-				enum ipa_rm_resource_name depends_on_name);
+				enum ipa_rm_resource_name depends_on_name,
+				bool userspsace_dep);
 
 int ipa_rm_dep_graph_delete_dependency(struct ipa_rm_dep_graph *graph,
 				enum ipa_rm_resource_name resource_name,
-				enum ipa_rm_resource_name depends_on_name);
+				enum ipa_rm_resource_name depends_on_name,
+				bool userspsace_dep);
 
 #endif /* _IPA_RM_DEPENDENCY_GRAPH_H_ */
diff --git a/drivers/platform/msm/ipa/ipa_rm_i.h b/drivers/platform/msm/ipa/ipa_rm_i.h
index e0c1582e8543..eb86c54d7382 100644
--- a/drivers/platform/msm/ipa/ipa_rm_i.h
+++ b/drivers/platform/msm/ipa/ipa_rm_i.h
@@ -146,6 +146,12 @@ int ipa_rm_request_resource_with_timer(enum ipa_rm_resource_name resource_name);
 
 void delayed_release_work_func(struct work_struct *work);
 
+int ipa_rm_add_dependency_from_ioctl(enum ipa_rm_resource_name resource_name,
+	enum ipa_rm_resource_name depends_on_name);
+
+int ipa_rm_delete_dependency_from_ioctl(enum ipa_rm_resource_name resource_name,
+	enum ipa_rm_resource_name depends_on_name);
+
 void ipa_rm_exit(void);
 
 #endif /* _IPA_RM_I_H_ */
diff --git a/drivers/platform/msm/ipa/ipa_rm_peers_list.c b/drivers/platform/msm/ipa/ipa_rm_peers_list.c
index 51ad9530f6ee..fe8e781c4db0 100644
--- a/drivers/platform/msm/ipa/ipa_rm_peers_list.c
+++ b/drivers/platform/msm/ipa/ipa_rm_peers_list.c
@@ -68,7 +68,7 @@ int ipa_rm_peers_list_create(int max_peers,
 
 	(*peers_list)->max_peers = max_peers;
 	(*peers_list)->peers = kzalloc((*peers_list)->max_peers *
-				sizeof(struct ipa_rm_resource *), GFP_ATOMIC);
+			sizeof(*((*peers_list)->peers)), GFP_ATOMIC);
 	if (!((*peers_list)->peers)) {
 		IPA_RM_ERR("no mem\n");
 		result = -ENOMEM;
@@ -112,7 +112,9 @@ void ipa_rm_peers_list_remove_peer(
 		return;
 
 	peers_list->peers[ipa_rm_peers_list_get_resource_index(
-			resource_name)] = NULL;
+			resource_name)].resource = NULL;
+	peers_list->peers[ipa_rm_peers_list_get_resource_index(
+			resource_name)].userspace_dep = false;
 	peers_list->peers_count--;
 }
 
@@ -125,14 +127,16 @@ void ipa_rm_peers_list_remove_peer(
  */
 void ipa_rm_peers_list_add_peer(
 		struct ipa_rm_peers_list *peers_list,
-		struct ipa_rm_resource *resource)
+		struct ipa_rm_resource *resource,
+		bool userspace_dep)
 {
 	if (!peers_list || !resource)
 		return;
 
 	peers_list->peers[ipa_rm_peers_list_get_resource_index(
-			resource->name)] =
-			resource;
+			resource->name)].resource = resource;
+	peers_list->peers[ipa_rm_peers_list_get_resource_index(
+		resource->name)].userspace_dep = userspace_dep;
 	peers_list->peers_count++;
 }
 
@@ -186,6 +190,7 @@ bail:
  * @resource_name: first peers list resource name
  * @depends_on_peers: second peers list
  * @depends_on_name: second peers list resource name
+ * @userspace_dep: [out] dependency was created by userspace
  *
  * Returns: true if there is dependency, false otherwise
  *
@@ -194,20 +199,28 @@ bool ipa_rm_peers_list_check_dependency(
 		struct ipa_rm_peers_list *resource_peers,
 		enum ipa_rm_resource_name resource_name,
 		struct ipa_rm_peers_list *depends_on_peers,
-		enum ipa_rm_resource_name depends_on_name)
+		enum ipa_rm_resource_name depends_on_name,
+		bool *userspace_dep)
 {
 	bool result = false;
+	int resource_index;
 
-	if (!resource_peers || !depends_on_peers)
+	if (!resource_peers || !depends_on_peers || !userspace_dep)
 		return result;
 
-	if (resource_peers->peers[ipa_rm_peers_list_get_resource_index(
-			depends_on_name)] != NULL)
+	resource_index = ipa_rm_peers_list_get_resource_index(depends_on_name);
+	if (resource_peers->peers[resource_index].resource != NULL) {
 		result = true;
+		*userspace_dep = resource_peers->peers[resource_index].
+			userspace_dep;
+	}
 
-	if (depends_on_peers->peers[ipa_rm_peers_list_get_resource_index(
-						resource_name)] != NULL)
+	resource_index = ipa_rm_peers_list_get_resource_index(resource_name);
+	if (depends_on_peers->peers[resource_index].resource != NULL) {
 		result = true;
+		*userspace_dep = depends_on_peers->peers[resource_index].
+			userspace_dep;
+	}
 
 	return result;
 }
@@ -228,7 +241,28 @@ struct ipa_rm_resource *ipa_rm_peers_list_get_resource(int resource_index,
 	if (!ipa_rm_peers_list_check_index(resource_index, resource_peers))
 		goto bail;
 
-	result = resource_peers->peers[resource_index];
+	result = resource_peers->peers[resource_index].resource;
+bail:
+	return result;
+}
+
+/**
+ * ipa_rm_peers_list_get_userspace_dep() - returns whether resource dependency
+ * was added by userspace
+ * @resource_index: resource index
+ * @resource_peers: peers list
+ *
+ * Returns: true if dependency was added by userspace, false by kernel
+ */
+bool ipa_rm_peers_list_get_userspace_dep(int resource_index,
+		struct ipa_rm_peers_list *resource_peers)
+{
+	bool result = false;
+
+	if (!ipa_rm_peers_list_check_index(resource_index, resource_peers))
+		goto bail;
+
+	result = resource_peers->peers[resource_index].userspace_dep;
 bail:
 	return result;
 }
diff --git a/drivers/platform/msm/ipa/ipa_rm_peers_list.h b/drivers/platform/msm/ipa/ipa_rm_peers_list.h
index b41de0aa3167..cf1c157174dc 100644
--- a/drivers/platform/msm/ipa/ipa_rm_peers_list.h
+++ b/drivers/platform/msm/ipa/ipa_rm_peers_list.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -15,6 +15,11 @@
 
 #include "ipa_rm_resource.h"
 
+struct ipa_rm_resource_peer {
+	struct ipa_rm_resource *resource;
+	bool userspace_dep;
+};
+
 /**
  * struct ipa_rm_peers_list - IPA RM resource peers list
  * @peers: the list of references to resources dependent on this resource
@@ -23,7 +28,7 @@
  * @peers_count: actual number of peers for this resource
  */
 struct ipa_rm_peers_list {
-	struct ipa_rm_resource		**peers;
+	struct ipa_rm_resource_peer	*peers;
 	int				max_peers;
 	int				peers_count;
 };
@@ -36,14 +41,18 @@ void ipa_rm_peers_list_remove_peer(
 		enum ipa_rm_resource_name resource_name);
 void ipa_rm_peers_list_add_peer(
 		struct ipa_rm_peers_list *peers_list,
-		struct ipa_rm_resource *resource);
+		struct ipa_rm_resource *resource,
+		bool userspace_dep);
 bool ipa_rm_peers_list_check_dependency(
 		struct ipa_rm_peers_list *resource_peers,
 		enum ipa_rm_resource_name resource_name,
 		struct ipa_rm_peers_list *depends_on_peers,
-		enum ipa_rm_resource_name depends_on_name);
+		enum ipa_rm_resource_name depends_on_name,
+		bool *userspace_dep);
 struct ipa_rm_resource *ipa_rm_peers_list_get_resource(int resource_index,
 		struct ipa_rm_peers_list *peers_list);
+bool ipa_rm_peers_list_get_userspace_dep(int resource_index,
+		struct ipa_rm_peers_list *resource_peers);
 int ipa_rm_peers_list_get_size(struct ipa_rm_peers_list *peers_list);
 bool ipa_rm_peers_list_is_empty(struct ipa_rm_peers_list *peers_list);
 bool ipa_rm_peers_list_has_last_peer(
diff --git a/drivers/platform/msm/ipa/ipa_rm_resource.c b/drivers/platform/msm/ipa/ipa_rm_resource.c
index 597598df6997..cc00f8cf7fb6 100644
--- a/drivers/platform/msm/ipa/ipa_rm_resource.c
+++ b/drivers/platform/msm/ipa/ipa_rm_resource.c
@@ -446,6 +446,7 @@ int ipa_rm_resource_delete(struct ipa_rm_resource *resource)
 	int peers_index;
 	int result = 0;
 	int list_size;
+	bool userspace_dep;
 
 	if (!resource) {
 		IPA_RM_ERR("invalid params\n");
@@ -464,10 +465,16 @@ int ipa_rm_resource_delete(struct ipa_rm_resource *resource)
 				consumer = ipa_rm_peers_list_get_resource(
 						peers_index,
 						resource->peers_list);
-				if (consumer)
+				if (consumer) {
+					userspace_dep =
+					ipa_rm_peers_list_get_userspace_dep(
+							peers_index,
+							resource->peers_list);
 					ipa_rm_resource_delete_dependency(
 						resource,
-						consumer);
+						consumer,
+						userspace_dep);
+				}
 			}
 		}
 
@@ -483,10 +490,16 @@ int ipa_rm_resource_delete(struct ipa_rm_resource *resource)
 				producer = ipa_rm_peers_list_get_resource(
 							peers_index,
 							resource->peers_list);
-				if (producer)
+				if (producer) {
+					userspace_dep =
+					ipa_rm_peers_list_get_userspace_dep(
+						peers_index,
+						resource->peers_list);
 					ipa_rm_resource_delete_dependency(
 							producer,
-							resource);
+							resource,
+							userspace_dep);
+				}
 			}
 		}
 	}
@@ -598,10 +611,12 @@ bail:
  * Returns: 0 on success, negative on failure
  */
 int ipa_rm_resource_add_dependency(struct ipa_rm_resource *resource,
-				   struct ipa_rm_resource *depends_on)
+				   struct ipa_rm_resource *depends_on,
+				   bool userspace_dep)
 {
 	int result = 0;
 	int consumer_result;
+	bool add_dep_by_userspace;
 
 	if (!resource || !depends_on) {
 		IPA_RM_ERR("invalid params\n");
@@ -611,13 +626,17 @@ int ipa_rm_resource_add_dependency(struct ipa_rm_resource *resource,
 	if (ipa_rm_peers_list_check_dependency(resource->peers_list,
 			resource->name,
 			depends_on->peers_list,
-			depends_on->name)) {
-		IPA_RM_ERR("dependency already exists\n");
+			depends_on->name,
+			&add_dep_by_userspace)) {
+		IPA_RM_ERR("dependency already exists, added by %s\n",
+			add_dep_by_userspace ? "userspace" : "kernel");
 		return -EEXIST;
 	}
 
-	ipa_rm_peers_list_add_peer(resource->peers_list, depends_on);
-	ipa_rm_peers_list_add_peer(depends_on->peers_list, resource);
+	ipa_rm_peers_list_add_peer(resource->peers_list, depends_on,
+		userspace_dep);
+	ipa_rm_peers_list_add_peer(depends_on->peers_list, resource,
+		userspace_dep);
 	IPA_RM_DBG("%s state: %d\n", ipa_rm_resource_str(resource->name),
 				resource->state);
 
@@ -671,12 +690,14 @@ bail:
  * will be sent to the RM client
  */
 int ipa_rm_resource_delete_dependency(struct ipa_rm_resource *resource,
-				   struct ipa_rm_resource *depends_on)
+				   struct ipa_rm_resource *depends_on,
+				   bool userspace_dep)
 {
 	int result = 0;
 	bool state_changed = false;
 	bool release_consumer = false;
 	enum ipa_rm_event evt;
+	bool add_dep_by_userspace;
 
 	if (!resource || !depends_on) {
 		IPA_RM_ERR("invalid params\n");
@@ -686,10 +707,24 @@ int ipa_rm_resource_delete_dependency(struct ipa_rm_resource *resource,
 	if (!ipa_rm_peers_list_check_dependency(resource->peers_list,
 			resource->name,
 			depends_on->peers_list,
-			depends_on->name)) {
+			depends_on->name,
+			&add_dep_by_userspace)) {
 		IPA_RM_ERR("dependency does not exist\n");
 		return -EINVAL;
 	}
+
+	/*
+	 * to avoid race conditions between kernel and userspace
+	 * need to check that the dependency was added by same entity
+	 */
+	if (add_dep_by_userspace != userspace_dep) {
+		IPA_RM_DBG("dependency was added by %s\n",
+			add_dep_by_userspace ? "userspace" : "kernel");
+		IPA_RM_DBG("ignore request to delete dependency by %s\n",
+			userspace_dep ? "userspace" : "kernel");
+		return 0;
+	}
+
 	IPA_RM_DBG("%s state: %d\n", ipa_rm_resource_str(resource->name),
 				resource->state);
 
diff --git a/drivers/platform/msm/ipa/ipa_rm_resource.h b/drivers/platform/msm/ipa/ipa_rm_resource.h
index 26573e243b4e..5c3a0190753f 100644
--- a/drivers/platform/msm/ipa/ipa_rm_resource.h
+++ b/drivers/platform/msm/ipa/ipa_rm_resource.h
@@ -116,10 +116,12 @@ int ipa_rm_resource_producer_deregister(struct ipa_rm_resource_prod *producer,
 				struct ipa_rm_register_params *reg_params);
 
 int ipa_rm_resource_add_dependency(struct ipa_rm_resource *resource,
-				   struct ipa_rm_resource *depends_on);
+				   struct ipa_rm_resource *depends_on,
+				   bool userspace_dep);
 
 int ipa_rm_resource_delete_dependency(struct ipa_rm_resource *resource,
-				      struct ipa_rm_resource *depends_on);
+				      struct ipa_rm_resource *depends_on,
+				      bool userspace_dep);
 
 int ipa_rm_resource_producer_request(struct ipa_rm_resource_prod *producer);
 
diff --git a/drivers/platform/msm/ipa/ipa_v2/ipa.c b/drivers/platform/msm/ipa/ipa_v2/ipa.c
index ae9e2b5a109d..1f9fd7a38a37 100644
--- a/drivers/platform/msm/ipa/ipa_v2/ipa.c
+++ b/drivers/platform/msm/ipa/ipa_v2/ipa.c
@@ -1116,8 +1116,8 @@ static long ipa_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			retval = -EFAULT;
 			break;
 		}
-		retval = ipa_rm_add_dependency(rm_depend.resource_name,
-						rm_depend.depends_on_name);
+		retval = ipa_rm_add_dependency_from_ioctl(
+			rm_depend.resource_name, rm_depend.depends_on_name);
 		break;
 	case IPA_IOC_RM_DEL_DEPENDENCY:
 		if (copy_from_user((u8 *)&rm_depend, (u8 *)arg,
@@ -1125,8 +1125,8 @@ static long ipa_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			retval = -EFAULT;
 			break;
 		}
-		retval = ipa_rm_delete_dependency(rm_depend.resource_name,
-						rm_depend.depends_on_name);
+		retval = ipa_rm_delete_dependency_from_ioctl(
+			rm_depend.resource_name, rm_depend.depends_on_name);
 		break;
 	case IPA_IOC_GENERATE_FLT_EQ:
 		{
diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa.c b/drivers/platform/msm/ipa/ipa_v3/ipa.c
index 7acf07acb8c1..747ae3d82b68 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa.c
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa.c
@@ -1196,8 +1196,8 @@ static long ipa3_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			retval = -EFAULT;
 			break;
 		}
-		retval = ipa_rm_add_dependency(rm_depend.resource_name,
-						rm_depend.depends_on_name);
+		retval = ipa_rm_add_dependency_from_ioctl(
+			rm_depend.resource_name, rm_depend.depends_on_name);
 		break;
 	case IPA_IOC_RM_DEL_DEPENDENCY:
 		if (copy_from_user((u8 *)&rm_depend, (u8 *)arg,
@@ -1205,8 +1205,8 @@ static long ipa3_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			retval = -EFAULT;
 			break;
 		}
-		retval = ipa_rm_delete_dependency(rm_depend.resource_name,
-						rm_depend.depends_on_name);
+		retval = ipa_rm_delete_dependency_from_ioctl(
+			rm_depend.resource_name, rm_depend.depends_on_name);
 		break;
 	case IPA_IOC_GENERATE_FLT_EQ:
 		{