[PATCH v4 0/8] staging: bcm2835-audio: fix coding style issues

[PATCH v4 0/8] staging: bcm2835-audio: fix coding style issues

[Aishwarya Pant]

This patch has the following fixes:

-- Replace kmalloc and memset with kzalloc vc_vchi_audio_init(..)
-- Replace null return value with PTR_ERR(..) values in
   vc_vchi_audio_init(..)
-- Propagate the PTR_ERR values forward instead of a hardcoded
   value for easier debugging in bcm2835_audio_open_connection(..)
-- Replace if (success) else { } after kmalloc with if(error)
   to fail fast in the work function
-- De-allocate 'work' when queue_work(..) fails in the work
   functions
-- Add current function names __func__ to debug and error logs in the
   work functions
-- De-allocate 'vchi_instance' when VCHI connection fails or VCHI audio 
   instance initialisation fails in bcm2835_audio_open_connection()
-- Remove BUG_ON() in bcm2835_audio_open_connection()


Changes in v4:
-- Break-up patch 4 into four smaller patches
-- Add a patch proposing removal of BUG_ON()
-- Make the cover letter verbose

Changes in v3:
-- Fix memory leak when queue_work fails
-- Add __func__ to debug logs

Changes in v2:
-- Return error value -EBUSY instead of -1 when queue_work()
   fails


Aishwarya Pant (8):
  staging: bcm2835-audio: Replace kmalloc with kzalloc
  staging: bcm2835-audio: replace null with error pointer value
  staging: bcm2835-audio: propagate PTR_ERR value instead of -EPERM
  staging: bcm2835-audio: use conditional only for error case
  staging: bcm2835-audio: deallocate work when queue_work(...) fails
  staging: bcm2835-audio: Add function name to debug and error logs
  staging: bcm2835-audio: fix memory leak in    
    bcm2835_audio_open_connection()
  staging: bcm2835-audio: remove BUG_ON() in
    bcm2835_audio_open_connection()

 .../vc04_services/bcm2835-audio/bcm2835-vchiq.c    | 109 +++++++++++----------
 1 file changed, 56 insertions(+), 53 deletions(-)

-- 
2.7.4

[PATCH v4 1/8] staging: bcm2835-audio: Replace kmalloc with kzalloc

[Aishwarya Pant]

Replace kmalloc and memset with kzalloc.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index c54bef3..005e287 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -290,11 +290,10 @@ vc_vchi_audio_init(VCHI_INSTANCE_T vchi_instance,
 		return NULL;
 	}
 	/* Allocate memory for this instance */
-	instance = kmalloc(sizeof(*instance), GFP_KERNEL);
+	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
 	if (!instance)
 		return NULL;
 
-	memset(instance, 0, sizeof(*instance));
 	instance->num_connections = num_connections;
 
 	/* Create a lock for exclusive, serialized VCHI connection access */
-- 
2.7.4

[PATCH v4 2/8] staging: bcm2835-audio: replace null with error pointer value

[Aishwarya Pant]

This patch replaces NULL values returned by vc_vchi_audio_init(...) with
error pointer values:
	- Return ERR_PTR(-EINVAL) when too many instances of audio
	  service are initialised
	- Return ERR_PTR(-ENOMEM) when kzalloc fails
	- RETURN ERR_PTR(-EPERM) when vchi connections fail to open

Similarly, a NULL check where vc_vchi_audio_init(...) is called is
replaced by IS_ERR(..)

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 005e287..d2686b4 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -287,12 +287,12 @@ vc_vchi_audio_init(VCHI_INSTANCE_T vchi_instance,
 		LOG_ERR("%s: unsupported number of connections %u (max=%u)\n",
 			__func__, num_connections, VCHI_MAX_NUM_CONNECTIONS);
 
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 	/* Allocate memory for this instance */
 	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
 	if (!instance)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	instance->num_connections = num_connections;
 
@@ -341,7 +341,7 @@ vc_vchi_audio_init(VCHI_INSTANCE_T vchi_instance,
 	kfree(instance);
 	LOG_ERR("%s: error\n", __func__);
 
-	return NULL;
+	return ERR_PTR(-EPERM);
 }
 
 static int vc_vchi_audio_deinit(struct bcm2835_audio_instance *instance)
@@ -432,7 +432,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 	/* Initialize an instance of the audio service */
 	instance = vc_vchi_audio_init(vchi_instance, &vchi_connection, 1);
 
-	if (!instance) {
+	if (IS_ERR(instance)) {
 		LOG_ERR("%s: failed to initialize audio service\n", __func__);
 
 		ret = -EPERM;
-- 
2.7.4

[PATCH v4 3/8] staging: bcm2835-audio: propagate PTR_ERR value instead of -EPERM

[Aishwarya Pant]

It is better to propagate PTR_ERR value instead of a hardcoded value
(-EPERM here)

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index d2686b4..c5f3be8 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -435,7 +435,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 	if (IS_ERR(instance)) {
 		LOG_ERR("%s: failed to initialize audio service\n", __func__);
 
-		ret = -EPERM;
+		ret = PTR_ERR(instance);
 		goto err_free_mem;
 	}
 
-- 
2.7.4

[PATCH v4 4/8] staging: bcm2835-audio: use conditional only for error case

[Aishwarya Pant]

* Refactor conditional to check if memory allocation has failed and
immediately return (-ENOMEM); if block for success case is removed.

* Return the error value -EBUSY when queue_work() fails.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>

---
Changes in v4:
	- Break up the patch into smaller changes
Changes in v3:
	- Deallocate work when queue_work fails
	- Add __func__ to debug logs
Changes in v2:
	- Return error value -EBUSY when queue_work fails

 .../vc04_services/bcm2835-audio/bcm2835-vchiq.c    | 67 +++++++++++-----------
 1 file changed, 32 insertions(+), 35 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index c5f3be8..9545d35 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -131,77 +131,74 @@ static void my_wq_function(struct work_struct *work)
 
 int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 {
-	int ret = -1;
-
 	LOG_DBG(" .. IN\n");
 	if (alsa_stream->my_wq) {
 		struct bcm2835_audio_work *work;
 
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
-		if (work) {
-			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))
-				ret = 0;
-		} else {
+		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)) {
+			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT %d\n", ret);
-	return ret;
+	LOG_DBG(" .. OUT\n");
+	return 0;
 }
 
 int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 {
-	int ret = -1;
-
 	LOG_DBG(" .. IN\n");
 	if (alsa_stream->my_wq) {
 		struct bcm2835_audio_work *work;
 
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
-		if (work) {
-			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))
-				ret = 0;
-		} else {
+		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)) {
+			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT %d\n", ret);
-	return ret;
+	LOG_DBG(" .. OUT\n");
+	return 0;
 }
 
 int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 			unsigned int count, void *src)
 {
-	int ret = -1;
-
 	LOG_DBG(" .. IN\n");
 	if (alsa_stream->my_wq) {
 		struct bcm2835_audio_work *work;
 
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
-		if (work) {
-			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))
-				ret = 0;
-		} else {
+		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)) {
+			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT %d\n", ret);
-	return ret;
+	LOG_DBG(" .. OUT\n");
+	return 0;
 }
 
 static void my_workqueue_init(struct bcm2835_alsa_stream *alsa_stream)
-- 
2.7.4

[PATCH v4 5/8] staging: bcm2835-audio: deallocate work when queue_work(...) fails

[Aishwarya Pant]

This patch de-allocates work when queue_work(..) fails in the
bcm2835-audio work functions

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 9545d35..026582e 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -145,6 +145,7 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 		work->alsa_stream = alsa_stream;
 		work->cmd = BCM2835_AUDIO_START;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+			kfree(work);
 			return -EBUSY;
 		}
 	}
@@ -168,6 +169,7 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 		work->alsa_stream = alsa_stream;
 		work->cmd = BCM2835_AUDIO_STOP;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+			kfree(work);
 			return -EBUSY;
 		}
 	}
@@ -194,6 +196,7 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 		work->src = src;
 		work->count = count;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
+			kfree(work);
 			return -EBUSY;
 		}
 	}
-- 
2.7.4

[PATCH v4 6/8] staging: bcm2835-audio: Add function name to debug and error logs

[Aishwarya Pant]

This patch adds current function names __func__ to debug and error logs
in the work functions.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 .../staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c   | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 026582e..77657a0 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -138,7 +138,7 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
 		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
+			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
 			return -ENOMEM;
 		}
 		INIT_WORK(&work->my_work, my_wq_function);
@@ -146,10 +146,11 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 		work->cmd = BCM2835_AUDIO_START;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
 			kfree(work);
+			LOG_ERR("%s: Error: Unable to start audio\n", __func__);
 			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT\n");
+	LOG_DBG("%s: .. OUT\n", __func__);
 	return 0;
 }
 
@@ -162,7 +163,7 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
 		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
+			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
 			return -ENOMEM;
 		}
 		INIT_WORK(&work->my_work, my_wq_function);
@@ -170,10 +171,11 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 		work->cmd = BCM2835_AUDIO_STOP;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
 			kfree(work);
+			LOG_ERR("%s: Error: Unable to stop audio\n", __func__);
 			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT\n");
+	LOG_DBG("%s: .. OUT\n", __func__);
 	return 0;
 }
 
@@ -187,7 +189,7 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
 		/*--- Queue some work (item 1) ---*/
 		if (!work) {
-			LOG_ERR(" .. Error: NULL work kmalloc\n");
+			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
 			return -ENOMEM;
 		}
 		INIT_WORK(&work->my_work, my_wq_function);
@@ -197,10 +199,11 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 		work->count = count;
 		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
 			kfree(work);
+			LOG_ERR("%s: Error: Unable to write\n", __func__);
 			return -EBUSY;
 		}
 	}
-	LOG_DBG(" .. OUT\n");
+	LOG_DBG("%s: .. OUT\n", __func__);
 	return 0;
 }
 
-- 
2.7.4

[PATCH v4 7/8] staging: bcm2835-audio: fix memory leak in bcm2835_audio_open_connection()

[Aishwarya Pant]

In bcm2835_audio_open_connection(), if VCHI connection fails or
initialisation of VCHI audio instance fails vchi_instance needs to be
deallocated otherwise it will cause a memory leak.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
---
 .../staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c    | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 77657a0..560fa12 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -408,7 +408,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 		instance->alsa_stream = alsa_stream;
 		alsa_stream->instance = instance;
 		ret = 0; // xxx todo -1;
-		goto err_free_mem;
+		goto err_init;
 	}
 
 	/* Initialize and create a VCHI connection */
@@ -419,7 +419,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 				__func__, ret);
 
 			ret = -EIO;
-			goto err_free_mem;
+			goto err_init;
 		}
 		ret = vchi_connect(NULL, 0, vchi_instance);
 		if (ret) {
@@ -427,7 +427,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 				__func__, ret);
 
 			ret = -EIO;
-			goto err_free_mem;
+			goto err_free_memory;
 		}
 		initted = 1;
 	}
@@ -439,7 +439,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 		LOG_ERR("%s: failed to initialize audio service\n", __func__);
 
 		ret = PTR_ERR(instance);
-		goto err_free_mem;
+		goto err_free_memory;
 	}
 
 	instance->alsa_stream = alsa_stream;
@@ -447,9 +447,11 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 
 	LOG_DBG(" success !\n");
 	ret = 0;
-err_free_mem:
+err_init:
 	LOG_DBG(" .. OUT\n");
-
+	return ret;
+err_free_memory:
+	kfree(vchi_instance);
 	return ret;
 }
 
-- 
2.7.4

[PATCH v4 8/8] staging: bcm2835-audio: remove BUG_ON() in bcm2835_audio_open_connection()

[Aishwarya Pant]

The presence of BUG_ON(instance) in bcm2835_audio_open_connection()
makes the next if(instance) block unreachable. The desired behaviour is
that the function should exit gracefully returning an operation not
permitted error value (-EPERM).

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>

---
Not sure of this change. This driver is still in staging so maybe then
BUG_ON() is required here for debugging. The kernel coding style document
suggests that BUG_ON() should never be used since it kills the current process.
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 560fa12..19e0f44 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -401,13 +401,12 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
 	LOG_DBG(" .. IN\n");
 
 	LOG_INFO("%s: start\n", __func__);
-	BUG_ON(instance);
 	if (instance) {
 		LOG_ERR("%s: VCHI instance already open (%p)\n",
 			__func__, instance);
 		instance->alsa_stream = alsa_stream;
 		alsa_stream->instance = instance;
-		ret = 0; // xxx todo -1;
+		ret = -EPERM;
 		goto err_init;
 	}
 
-- 
2.7.4

Re: [PATCH v4 6/8] staging: bcm2835-audio: Add function name to debug and error logs

[Aishwarya Pant]

On Wed, Mar 08, 2017 at 08:19:51PM +0530, Aishwarya Pant wrote:
> This patch adds current function names __func__ to debug and error logs
> in the work functions.
> 
> Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
> ---
>  .../staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c   | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> index 026582e..77657a0 100644
> --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> @@ -138,7 +138,7 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
>  		work = kmalloc(sizeof(*work), GFP_ATOMIC);
>  		/*--- Queue some work (item 1) ---*/
>  		if (!work) {
> -			LOG_ERR(" .. Error: NULL work kmalloc\n");
> +			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
>  			return -ENOMEM;
>  		}
>  		INIT_WORK(&work->my_work, my_wq_function);
> @@ -146,10 +146,11 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
>  		work->cmd = BCM2835_AUDIO_START;
>  		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
>  			kfree(work);
> +			LOG_ERR("%s: Error: Unable to start audio\n", __func__);
>  			return -EBUSY;
>  		}
>  	}
> -	LOG_DBG(" .. OUT\n");
> +	LOG_DBG("%s: .. OUT\n", __func__);
>  	return 0;
>  }
>  
> @@ -162,7 +163,7 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
>  		work = kmalloc(sizeof(*work), GFP_ATOMIC);
>  		/*--- Queue some work (item 1) ---*/
>  		if (!work) {
> -			LOG_ERR(" .. Error: NULL work kmalloc\n");
> +			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
>  			return -ENOMEM;
>  		}
>  		INIT_WORK(&work->my_work, my_wq_function);
> @@ -170,10 +171,11 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
>  		work->cmd = BCM2835_AUDIO_STOP;
>  		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
>  			kfree(work);
> +			LOG_ERR("%s: Error: Unable to stop audio\n", __func__);
>  			return -EBUSY;
>  		}
>  	}
> -	LOG_DBG(" .. OUT\n");
> +	LOG_DBG("%s: .. OUT\n", __func__);
>  	return 0;
>  }
>  
> @@ -187,7 +189,7 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
>  		work = kmalloc(sizeof(*work), GFP_ATOMIC);
>  		/*--- Queue some work (item 1) ---*/
>  		if (!work) {
> -			LOG_ERR(" .. Error: NULL work kmalloc\n");
> +			LOG_ERR("%s: Error: NULL work kmalloc\n", __func__);
>  			return -ENOMEM;
>  		}
>  		INIT_WORK(&work->my_work, my_wq_function);
> @@ -197,10 +199,11 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
>  		work->count = count;
>  		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
>  			kfree(work);
> +			LOG_ERR("%s: Error: Unable to write\n", __func__);
>  			return -EBUSY;
>  		}
>  	}
> -	LOG_DBG(" .. OUT\n");
> +	LOG_DBG("%s: .. OUT\n", __func__);


Please ignore this patch.
LOG_DBG/ERR/INFO(..) are wrappers around pr_*(..) family with line 
number and function name appended. I'll send a new patchset with 
these changes reverted.



>  	return 0;
>  }
>  
> -- 
> 2.7.4
>