From 4feb0f375f030050906c834fde8bf80ac4a4571b Mon Sep 17 00:00:00 2001
From: Tuomas Tynkkynen <tuomas@tuxera.com>
Date: Fri, 13 Jul 2018 00:54:16 +0300
Subject: [PATCH] staging: bcm2835-audio: Check if workqueue allocation failed
Git-commit: 4feb0f375f030050906c834fde8bf80ac4a4571b
Patch-mainline: v4.19-rc1
References: FATE#324827

Currently, if allocating a workqueue fails, the driver will probe
successfully but it will silently do nothing, which is rather silly.
So instead bail out with -ENOMEM in bcm2835_audio_open() if
alloc_workqueue() fails, and remove the now pointless checks for a NULL
workqueue.

While at it, get rid of the rather pointless one-line function
my_workqueue_init().

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c |  105 +++++-------
 1 file changed, 47 insertions(+), 58 deletions(-)

--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -117,44 +117,40 @@ static void my_wq_function(struct work_s
 
 int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
-		struct bcm2835_audio_work *work;
+	struct bcm2835_audio_work *work;
 
-		work = kmalloc(sizeof(*work), GFP_ATOMIC);
-		/*--- Queue some work (item 1) ---*/
-		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
-			return -ENOMEM;
-		}
-		INIT_WORK(&work->my_work, my_wq_function);
-		work->alsa_stream = alsa_stream;
-		work->cmd = BCM2835_AUDIO_START;
-		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
-			kfree(work);
-			return -EBUSY;
-		}
+	work = kmalloc(sizeof(*work), GFP_ATOMIC);
+	/*--- Queue some work (item 1) ---*/
+	if (!work) {
+		LOG_ERR(" .. Error: NULL work kmalloc\n");
+		return -ENOMEM;
+	}
+	INIT_WORK(&work->my_work, my_wq_function);
+	work->alsa_stream = alsa_stream;
+	work->cmd = BCM2835_AUDIO_START;
+	if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+		kfree(work);
+		return -EBUSY;
 	}
 	return 0;
 }
 
 int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
-		struct bcm2835_audio_work *work;
+	struct bcm2835_audio_work *work;
 
-		work = kmalloc(sizeof(*work), GFP_ATOMIC);
-		/*--- Queue some work (item 1) ---*/
-		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
-			return -ENOMEM;
-		}
-		INIT_WORK(&work->my_work, my_wq_function);
-		work->alsa_stream = alsa_stream;
-		work->cmd = BCM2835_AUDIO_STOP;
-		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
-			kfree(work);
-			return -EBUSY;
-		}
+	work = kmalloc(sizeof(*work), GFP_ATOMIC);
+	/*--- Queue some work (item 1) ---*/
+	if (!work) {
+		LOG_ERR(" .. Error: NULL work kmalloc\n");
+		return -ENOMEM;
+	}
+	INIT_WORK(&work->my_work, my_wq_function);
+	work->alsa_stream = alsa_stream;
+	work->cmd = BCM2835_AUDIO_STOP;
+	if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+		kfree(work);
+		return -EBUSY;
 	}
 	return 0;
 }
@@ -162,40 +158,31 @@ int bcm2835_audio_stop(struct bcm2835_al
 int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 			unsigned int count, void *src)
 {
-	if (alsa_stream->my_wq) {
-		struct bcm2835_audio_work *work;
+	struct bcm2835_audio_work *work;
 
-		work = kmalloc(sizeof(*work), GFP_ATOMIC);
-		/*--- Queue some work (item 1) ---*/
-		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
-			return -ENOMEM;
-		}
-		INIT_WORK(&work->my_work, my_wq_function);
-		work->alsa_stream = alsa_stream;
-		work->cmd = BCM2835_AUDIO_WRITE;
-		work->src = src;
-		work->count = count;
-		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
-			kfree(work);
-			return -EBUSY;
-		}
+	work = kmalloc(sizeof(*work), GFP_ATOMIC);
+	/*--- Queue some work (item 1) ---*/
+	if (!work) {
+		LOG_ERR(" .. Error: NULL work kmalloc\n");
+		return -ENOMEM;
+	}
+	INIT_WORK(&work->my_work, my_wq_function);
+	work->alsa_stream = alsa_stream;
+	work->cmd = BCM2835_AUDIO_WRITE;
+	work->src = src;
+	work->count = count;
+	if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+		kfree(work);
+		return -EBUSY;
 	}
 	return 0;
 }
 
-static void my_workqueue_init(struct bcm2835_alsa_stream *alsa_stream)
-{
-	alsa_stream->my_wq = alloc_workqueue("my_queue", WQ_HIGHPRI, 1);
-}
-
 static void my_workqueue_quit(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
-		flush_workqueue(alsa_stream->my_wq);
-		destroy_workqueue(alsa_stream->my_wq);
-		alsa_stream->my_wq = NULL;
-	}
+	flush_workqueue(alsa_stream->my_wq);
+	destroy_workqueue(alsa_stream->my_wq);
+	alsa_stream->my_wq = NULL;
 }
 
 static void audio_vchi_callback(void *param,
@@ -436,7 +423,9 @@ int bcm2835_audio_open(struct bcm2835_al
 	int status;
 	int ret;
 
-	my_workqueue_init(alsa_stream);
+	alsa_stream->my_wq = alloc_workqueue("my_queue", WQ_HIGHPRI, 1);
+	if (!alsa_stream->my_wq)
+		return -ENOMEM;
 
 	ret = bcm2835_audio_open_connection(alsa_stream);
 	if (ret) {