LWIS: Remove tasklet context for LWIS transactions

Bug: 239605455
Test: atest LwisClientAndroidTest, atest android.hardware.camera2.cts.PerformanceTest
Signed-off-by: linyuny <linyuny@google.com>
Change-Id: I1fe1cedcbbffdb339287563bfe668feac7058631

2 files changed, 12 insertions, 50 deletions

diff --git a/lwis_device.h b/lwis_device.h
index ea62088..2e19917 100644
--- a/lwis_device.h
+++ b/lwis_device.h
@@ -316,12 +316,9 @@ struct lwis_client {
 	DECLARE_HASHTABLE(enrolled_buffers, BUFFER_HASH_BITS);
 	/* Hash table of transactions keyed by trigger event ID */
 	DECLARE_HASHTABLE(transaction_list, TRANSACTION_HASH_BITS);
-	/* Transaction task-related variables */
-	struct tasklet_struct transaction_tasklet;
 	/* Spinlock used to synchronize access to transaction data structs */
 	spinlock_t transaction_lock;
 	/* List of transaction triggers */
-	struct list_head transaction_process_queue_tasklet;
 	struct list_head transaction_process_queue;
 	/* Transaction counter, which also provides transacton ID */
 	int64_t transaction_counter;
diff --git a/lwis_transaction.c b/lwis_transaction.c
index 1ba981a..05aa3b6 100644
--- a/lwis_transaction.c
+++ b/lwis_transaction.c
@@ -349,20 +349,20 @@ static void cancel_transaction(struct lwis_device *lwis_dev, struct lwis_transac
 	lwis_transaction_free(lwis_dev, transaction);
 }
 
-static void process_transactions_in_queue(struct lwis_client *client,
-					  struct list_head *transaction_queue, bool in_irq)
+static void transaction_work_func(struct kthread_work *work)
 {
 	unsigned long flags;
-	struct lwis_transaction *transaction;
+	struct lwis_client *client = container_of(work, struct lwis_client, transaction_work);
 	struct list_head *it_tran, *it_tran_tmp;
 	struct list_head pending_events;
 	struct list_head pending_fences;
+	struct lwis_transaction *transaction;
 
 	INIT_LIST_HEAD(&pending_events);
 	INIT_LIST_HEAD(&pending_fences);
 
 	spin_lock_irqsave(&client->transaction_lock, flags);
-	list_for_each_safe (it_tran, it_tran_tmp, transaction_queue) {
+	list_for_each_safe (it_tran, it_tran_tmp, &client->transaction_process_queue) {
 		transaction = list_entry(it_tran, struct lwis_transaction, process_queue_node);
 		list_del(&transaction->process_queue_node);
 		if (transaction->resp->error_code) {
@@ -372,36 +372,20 @@ static void process_transactions_in_queue(struct lwis_client *client,
 		} else {
 			spin_unlock_irqrestore(&client->transaction_lock, flags);
 			process_transaction(client, transaction, &pending_events, &pending_fences,
-					    in_irq,
+					    /*in_irq=*/false,
 					    /*skip_err=*/false);
 			spin_lock_irqsave(&client->transaction_lock, flags);
 		}
 	}
 	spin_unlock_irqrestore(&client->transaction_lock, flags);
 
-	lwis_pending_events_emit(client->lwis_dev, &pending_events, in_irq);
+	lwis_pending_events_emit(client->lwis_dev, &pending_events, /*in_irq=*/false);
 	lwis_fences_pending_signal_emit(client->lwis_dev, &pending_fences);
 }
 
-static void transaction_tasklet_func(unsigned long data)
-{
-	struct lwis_client *client = (struct lwis_client *)data;
-
-	process_transactions_in_queue(client, &client->transaction_process_queue_tasklet,
-				      /*in_irq=*/true);
-}
-
-static void transaction_work_func(struct kthread_work *work)
-{
-	struct lwis_client *client = container_of(work, struct lwis_client, transaction_work);
-	process_transactions_in_queue(client, &client->transaction_process_queue, /*in_irq=*/false);
-}
-
 int lwis_transaction_init(struct lwis_client *client)
 {
 	spin_lock_init(&client->transaction_lock);
-	INIT_LIST_HEAD(&client->transaction_process_queue_tasklet);
-	tasklet_init(&client->transaction_tasklet, transaction_tasklet_func, (unsigned long)client);
 	INIT_LIST_HEAD(&client->transaction_process_queue);
 	kthread_init_work(&client->transaction_work, transaction_work_func);
 	client->transaction_counter = 0;
@@ -420,7 +404,6 @@ int lwis_transaction_clear(struct lwis_client *client)
 			"Failed to wait for all in-process transactions to complete (%d)\n", ret);
 		return ret;
 	}
-	tasklet_kill(&client->transaction_tasklet);
 	return 0;
 }
 
@@ -478,18 +461,12 @@ int lwis_transaction_client_flush(struct lwis_client *client)
 	if (client->lwis_dev->transaction_worker_thread)
 		kthread_flush_worker(&client->lwis_dev->transaction_worker);
 
-	/* Wait for tasklet to complete in-progress transactions and disable. */
-	tasklet_disable(&client->transaction_tasklet);
-
 	spin_lock_irqsave(&client->transaction_lock, flags);
-	/* Both transaction queues should be empty after draining, but check anyway. */
+	/* The transaction queue should be empty after canceling all transactions,
+	 * but check anyway. */
 	cancel_all_transactions_in_queue_locked(client, &client->transaction_process_queue);
-	cancel_all_transactions_in_queue_locked(client, &client->transaction_process_queue_tasklet);
 	spin_unlock_irqrestore(&client->transaction_lock, flags);
 
-	/* Resume the tasklet once making sure transactions are all flushed. */
-	tasklet_enable(&client->transaction_tasklet);
-
 	return 0;
 }
 
@@ -768,16 +745,10 @@ static int queue_transaction_locked(struct lwis_client *client,
 
 	if (transaction->queue_immediately) {
 		/* Immediate trigger. */
-		if (info->run_at_real_time) {
-			list_add_tail(&transaction->process_queue_node,
-				      &client->transaction_process_queue_tasklet);
-			tasklet_schedule(&client->transaction_tasklet);
-		} else {
-			list_add_tail(&transaction->process_queue_node,
-				      &client->transaction_process_queue);
-			kthread_queue_work(&client->lwis_dev->transaction_worker,
-					   &client->transaction_work);
-		}
+		list_add_tail(&transaction->process_queue_node,
+			&client->transaction_process_queue);
+		kthread_queue_work(&client->lwis_dev->transaction_worker,
+			&client->transaction_work);
 	} else if (lwis_triggered_by_condition(transaction)) {
 		/* Trigger by trigger conditions. */
 		add_pending_transaction(client, transaction);
@@ -878,9 +849,6 @@ static void defer_transaction_locked(struct lwis_client *client,
 		process_transaction(client, transaction, pending_events, pending_fences, in_irq,
 				    /*skip_err=*/false);
 		spin_lock_irqsave(&client->transaction_lock, flags);
-	} else if (transaction->info.run_at_real_time) {
-		list_add_tail(&transaction->process_queue_node,
-			      &client->transaction_process_queue_tasklet);
 	} else {
 		list_add_tail(&transaction->process_queue_node, &client->transaction_process_queue);
 	}
@@ -974,9 +942,6 @@ int lwis_transaction_event_trigger(struct lwis_client *client, int64_t event_id,
 	}
 
 	/* Schedule deferred transactions */
-	if (!list_empty(&client->transaction_process_queue_tasklet)) {
-		tasklet_schedule(&client->transaction_tasklet);
-	}
 	if (!list_empty(&client->transaction_process_queue)) {
 		kthread_queue_work(&client->lwis_dev->transaction_worker,
 				   &client->transaction_work);