[PATCH v2] spi: use kthread_create_worker() helper

[PATCH v2] spi: use kthread_create_worker() helper

[Marek Szyprowski]

Use kthread_create_worker() helper to simplify the code. It uses
the kthread worker API the right way. It will eventually allow
to remove the FIXME in kthread_worker_fn() and add more consistency
checks in the future.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
v2:
- changed patch description, removed stack dump
---
 drivers/spi/spi.c       | 26 ++++++++++++--------------
 include/linux/spi/spi.h |  6 ++----
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 805a51b6f54c..19a03a8d6199 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1368,7 +1368,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
 
 	/* If another context is idling the device then defer */
 	if (ctlr->idling) {
-		kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+		kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return;
 	}
@@ -1382,7 +1382,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
 
 		/* Only do teardown in the thread */
 		if (!in_kthread) {
-			kthread_queue_work(&ctlr->kworker,
+			kthread_queue_work(ctlr->kworker,
 					   &ctlr->pump_messages);
 			spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 			return;
@@ -1616,7 +1616,7 @@ static void spi_set_thread_rt(struct spi_controller *ctlr)
 {
 	dev_info(&ctlr->dev,
 		"will run message pump with realtime priority\n");
-	sched_set_fifo(ctlr->kworker_task);
+	sched_set_fifo(ctlr->kworker->task);
 }
 
 static int spi_init_queue(struct spi_controller *ctlr)
@@ -1624,13 +1624,12 @@ static int spi_init_queue(struct spi_controller *ctlr)
 	ctlr->running = false;
 	ctlr->busy = false;
 
-	kthread_init_worker(&ctlr->kworker);
-	ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
-					 "%s", dev_name(&ctlr->dev));
-	if (IS_ERR(ctlr->kworker_task)) {
-		dev_err(&ctlr->dev, "failed to create message pump task\n");
-		return PTR_ERR(ctlr->kworker_task);
+	ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
+	if (IS_ERR(ctlr->kworker)) {
+		dev_err(&ctlr->dev, "failed to create message pump kworker\n");
+		return PTR_ERR(ctlr->kworker);
 	}
+
 	kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
 
 	/*
@@ -1714,7 +1713,7 @@ void spi_finalize_current_message(struct spi_controller *ctlr)
 	ctlr->cur_msg = NULL;
 	ctlr->cur_msg_prepared = false;
 	ctlr->fallback = false;
-	kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
 	trace_spi_message_done(mesg);
@@ -1740,7 +1739,7 @@ static int spi_start_queue(struct spi_controller *ctlr)
 	ctlr->cur_msg = NULL;
 	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
-	kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 
 	return 0;
 }
@@ -1796,8 +1795,7 @@ static int spi_destroy_queue(struct spi_controller *ctlr)
 		return ret;
 	}
 
-	kthread_flush_worker(&ctlr->kworker);
-	kthread_stop(ctlr->kworker_task);
+	kthread_destroy_worker(ctlr->kworker);
 
 	return 0;
 }
@@ -1820,7 +1818,7 @@ static int __spi_queued_transfer(struct spi_device *spi,
 
 	list_add_tail(&msg->queue, &ctlr->queue);
 	if (!ctlr->busy && need_pump)
-		kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+		kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 
 	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 	return 0;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 0e67a9a3a1d3..5fcf5da13fdb 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -358,8 +358,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @cleanup: frees controller-specific state
  * @can_dma: determine whether this controller supports DMA
  * @queued: whether this controller is providing an internal message queue
- * @kworker: thread struct for message pump
- * @kworker_task: pointer to task for message pump kworker thread
+ * @kworker: pointer to thread struct for message pump
  * @pump_messages: work struct for scheduling work to the message pump
  * @queue_lock: spinlock to syncronise access to message queue
  * @queue: message queue
@@ -593,8 +592,7 @@ struct spi_controller {
 	 * Over time we expect SPI drivers to be phased over to this API.
 	 */
 	bool				queued;
-	struct kthread_worker		kworker;
-	struct task_struct		*kworker_task;
+	struct kthread_worker		*kworker;
 	struct kthread_work		pump_messages;
 	spinlock_t			queue_lock;
 	struct list_head		queue;
-- 
2.17.1

Re: [PATCH v2] spi: use kthread_create_worker() helper

[Mark Brown]

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On Wed, Jul 08, 2020 at 02:33:49PM +0200, Marek Szyprowski wrote:
> Use kthread_create_worker() helper to simplify the code. It uses
> the kthread worker API the right way. It will eventually allow
> to remove the FIXME in kthread_worker_fn() and add more consistency
> checks in the future.

This doesn't apply against current code, please check and resend.

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Re: [PATCH v2] spi: use kthread_create_worker() helper

[Mark Brown]

On Wed, 8 Jul 2020 14:33:49 +0200, Marek Szyprowski wrote:
> Use kthread_create_worker() helper to simplify the code. It uses
> the kthread worker API the right way. It will eventually allow
> to remove the FIXME in kthread_worker_fn() and add more consistency
> checks in the future.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: use kthread_create_worker() helper
      commit: 60a883d119ab9ef63f830c85bbd2f0e2e2314f4f

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark