[2/2,RFC] spi/bitbang: Use a kthread worker instead of workqueue

Commit Message

Uwe Kleine-König Feb. 8, 2011, 9:46 a.m. UTC

None

Patch

diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 14a63f6..e2a874a 100644
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -254,7 +254,7 @@  static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
  * Drivers can provide word-at-a-time i/o primitives, or provide
  * transfer-at-a-time ones to leverage dma or fifo hardware.
  */
-static void bitbang_work(struct work_struct *work)
+static void bitbang_work(struct kthread_work *work)
 {
 	struct spi_bitbang	*bitbang =
 		container_of(work, struct spi_bitbang, work);
@@ -396,7 +396,7 @@  int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
 		status = -ENETDOWN;
 	else {
 		list_add_tail(&m->queue, &bitbang->queue);
-		queue_work(bitbang->workqueue, &bitbang->work);
+		queue_kthread_work(&bitbang->worker, &bitbang->work);
 	}
 	spin_unlock_irqrestore(&bitbang->lock, flags);
 
@@ -432,11 +432,12 @@  EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
 int spi_bitbang_start(struct spi_bitbang *bitbang)
 {
 	int	status;
+	struct sched_param param = { .sched_priority = 49 };
 
 	if (!bitbang->master || !bitbang->chipselect)
 		return -EINVAL;
 
-	INIT_WORK(&bitbang->work, bitbang_work);
+	init_kthread_work(&bitbang->work, bitbang_work);
 	spin_lock_init(&bitbang->lock);
 	INIT_LIST_HEAD(&bitbang->queue);
 
@@ -463,12 +464,14 @@  int spi_bitbang_start(struct spi_bitbang *bitbang)
 
 	/* this task is the only thing to touch the SPI bits */
 	bitbang->busy = 0;
-	bitbang->workqueue = create_singlethread_workqueue(
+	init_kthread_worker(&bitbang->worker);
+	bitbang->worker_task = kthread_run(kthread_worker_fn, &bitbang->worker,
 			dev_name(bitbang->master->dev.parent));
-	if (bitbang->workqueue == NULL) {
+	if (bitbang->worker_task == NULL) {
 		status = -EBUSY;
 		goto err1;
 	}
+	sched_setscheduler(bitbang->worker_task, SCHED_FIFO, &param);
 
 	/* driver may get busy before register() returns, especially
 	 * if someone registered boardinfo for devices
@@ -480,7 +483,7 @@  int spi_bitbang_start(struct spi_bitbang *bitbang)
 	return status;
 
 err2:
-	destroy_workqueue(bitbang->workqueue);
+	kthread_stop(bitbang->worker_task);
 err1:
 	return status;
 }
@@ -495,7 +498,7 @@  int spi_bitbang_stop(struct spi_bitbang *bitbang)
 
 	WARN_ON(!list_empty(&bitbang->queue));
 
-	destroy_workqueue(bitbang->workqueue);
+	kthread_stop(bitbang->worker_task);
 
 	return 0;
 }
diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index f987a2b..36bb3be 100644
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -1,11 +1,12 @@ 
 #ifndef	__SPI_BITBANG_H
 #define	__SPI_BITBANG_H
 
-#include <linux/workqueue.h>
+#include <linux/kthread.h>
 
 struct spi_bitbang {
-	struct workqueue_struct	*workqueue;
-	struct work_struct	work;
+	struct kthread_worker	worker;
+	struct task_struct	*worker_task;
+	struct kthread_work	work;
 
 	spinlock_t		lock;
 	struct list_head	queue;