msm: ipa: Fix the problem with nested sleeping primitives

prepare_to_wait() will enqueue the thread on the given queue
and put it into the given execution state,
which is TASK_INTERRUPTIBLE.

Further processing in function, calls  mutex_lock(),
will go into a new version of the going-to-sleep code,
changing the task state.

That, of course, may well interfere with the outer
sleeping code.

So, nesting of sleeping primitives in this way is discouraged.

And new warning was added to point out this kind of nesting.

Fix the nesting of sleeping primitives with the new solution
provide in linux kernel.

Change-Id: Id1a5f64472cd2d63e679706c6482db98f89ec765
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>

2 files changed, 8 insertions, 10 deletions

diff --git a/drivers/platform/msm/ipa/ipa_v2/ipa_intf.c b/drivers/platform/msm/ipa/ipa_v2/ipa_intf.c
index 5c07bc7d43b5..e3f987d47692 100644
--- a/drivers/platform/msm/ipa/ipa_v2/ipa_intf.c
+++ b/drivers/platform/msm/ipa/ipa_v2/ipa_intf.c
@@ -541,15 +541,15 @@ ssize_t ipa_read(struct file *filp, char __user *buf, size_t count,
 	char __user *start;
 	struct ipa_push_msg *msg = NULL;
 	int ret;
-	DEFINE_WAIT(wait);
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	int locked;
 
 	start = buf;
 
+	add_wait_queue(&ipa_ctx->msg_waitq, &wait);
 	while (1) {
 		mutex_lock(&ipa_ctx->msg_lock);
 		locked = 1;
-		prepare_to_wait(&ipa_ctx->msg_waitq, &wait, TASK_INTERRUPTIBLE);
 		if (!list_empty(&ipa_ctx->msg_list)) {
 			msg = list_first_entry(&ipa_ctx->msg_list,
 					struct ipa_push_msg, link);
@@ -601,10 +601,10 @@ ssize_t ipa_read(struct file *filp, char __user *buf, size_t count,
 
 		locked = 0;
 		mutex_unlock(&ipa_ctx->msg_lock);
-		schedule();
+		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 	}
 
-	finish_wait(&ipa_ctx->msg_waitq, &wait);
+	remove_wait_queue(&ipa_ctx->msg_waitq, &wait);
 	if (start != buf && ret != -EFAULT)
 		ret = buf - start;
 
diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa_intf.c b/drivers/platform/msm/ipa/ipa_v3/ipa_intf.c
index 16a567644f79..38e8d4e9d639 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa_intf.c
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa_intf.c
@@ -546,17 +546,15 @@ ssize_t ipa3_read(struct file *filp, char __user *buf, size_t count,
 	char __user *start;
 	struct ipa3_push_msg *msg = NULL;
 	int ret;
-	DEFINE_WAIT(wait);
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	int locked;
 
 	start = buf;
 
+	add_wait_queue(&ipa3_ctx->msg_waitq, &wait);
 	while (1) {
 		mutex_lock(&ipa3_ctx->msg_lock);
 		locked = 1;
-		prepare_to_wait(&ipa3_ctx->msg_waitq,
-				&wait,
-				TASK_INTERRUPTIBLE);
 
 		if (!list_empty(&ipa3_ctx->msg_list)) {
 			msg = list_first_entry(&ipa3_ctx->msg_list,
@@ -609,10 +607,10 @@ ssize_t ipa3_read(struct file *filp, char __user *buf, size_t count,
 
 		locked = 0;
 		mutex_unlock(&ipa3_ctx->msg_lock);
-		schedule();
+		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 	}
 
-	finish_wait(&ipa3_ctx->msg_waitq, &wait);
+	remove_wait_queue(&ipa3_ctx->msg_waitq, &wait);
 	if (start != buf && ret != -EFAULT)
 		ret = buf - start;