[PATCH] dma: pl330: fix a couple of compilation warnings

[PATCH] dma: pl330: fix a couple of compilation warnings

[Olof Johansson]

Move a couple of tests and do a minor refactor to avoid:

drivers/dma/pl330.c: In function 'pl330_probe':
drivers/dma/pl330.c:2929:215: warning: comparison of distinct pointer types lacks a cast [enabled by default]
drivers/dma/pl330.c: In function 'pl330_tasklet':
drivers/dma/pl330.c:2250:8: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
drivers/dma/pl330.c:2228:25: note: 'pch' was declared here
drivers/dma/pl330.c:2277:130: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
drivers/dma/pl330.c:2260:25: note: 'pch' was declared here

Signed-off-by: Olof Johansson <olof@lixom.net>
---
 drivers/dma/pl330.c |   23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 282caf11..ee0de4b 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2225,12 +2225,9 @@ static inline void free_desc_list(struct list_head *list)
 {
 	struct dma_pl330_dmac *pdmac;
 	struct dma_pl330_desc *desc;
-	struct dma_pl330_chan *pch;
+	struct dma_pl330_chan *pch = NULL;
 	unsigned long flags;
 
-	if (list_empty(list))
-		return;
-
 	/* Finish off the work list */
 	list_for_each_entry(desc, list, node) {
 		dma_async_tx_callback callback;
@@ -2247,6 +2244,10 @@ static inline void free_desc_list(struct list_head *list)
 		desc->pchan = NULL;
 	}
 
+	/* pch will be unset if list was empty */
+	if (!pch)
+		return;
+
 	pdmac = pch->dmac;
 
 	spin_lock_irqsave(&pdmac->pool_lock, flags);
@@ -2257,12 +2258,9 @@ static inline void free_desc_list(struct list_head *list)
 static inline void handle_cyclic_desc_list(struct list_head *list)
 {
 	struct dma_pl330_desc *desc;
-	struct dma_pl330_chan *pch;
+	struct dma_pl330_chan *pch = NULL;
 	unsigned long flags;
 
-	if (list_empty(list))
-		return;
-
 	list_for_each_entry(desc, list, node) {
 		dma_async_tx_callback callback;
 
@@ -2274,6 +2272,10 @@ static inline void handle_cyclic_desc_list(struct list_head *list)
 			callback(desc->txd.callback_param);
 	}
 
+	/* pch will be unset if list was empty */
+	if (!pch)
+		return;
+
 	spin_lock_irqsave(&pch->lock, flags);
 	list_splice_tail_init(list, &pch->work_list);
 	spin_unlock_irqrestore(&pch->lock, flags);
@@ -2926,8 +2928,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 	INIT_LIST_HEAD(&pd->channels);
 
 	/* Initialize channel parameters */
-	num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
-			(u8)pi->pcfg.num_chan);
+	num_chan = max_t(int, pdat ? pdat->nr_valid_peri :
+				     pi->pcfg.num_peri,
+			      pi->pcfg.num_chan);
 	pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
 
 	for (i = 0; i < num_chan; i++) {
-- 
1.7.9.2.359.gebfc2

Re: [PATCH] dma: pl330: fix a couple of compilation warnings

[Joe Perches]

On Sun, 2012-04-08 at 14:18 -0700, Olof Johansson wrote:
> Move a couple of tests and do a minor refactor to avoid:
[]
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
[]
> @@ -2926,8 +2928,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>  	INIT_LIST_HEAD(&pd->channels);
>  
>  	/* Initialize channel parameters */
> -	num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
> -			(u8)pi->pcfg.num_chan);
> +	num_chan = max_t(int, pdat ? pdat->nr_valid_peri :
> +				     pi->pcfg.num_peri,
> +			      pi->pcfg.num_chan);
>  	pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);

Few trivial things:

There's no error checking for a malloc failure
This should probably be kcalloc
The alignment here is not nice

Maybe:

	num_chan = max_t(size_t, pdat ? pdat->nr_valid_peri : pi->pcfg.num_peri,
			 pi->pcfg.num_chan);
	pdmac->peripherals = kcalloc(num_chan, sizeof(*pch), GFP_KERNEL);
	if (!pdmac->peripherals)
		goto some_err;

Re: [PATCH] dma: pl330: fix a couple of compilation warnings

[Olof Johansson]

On Sun, Apr 8, 2012 at 2:40 PM, Joe Perches <joe@perches.com> wrote:
> On Sun, 2012-04-08 at 14:18 -0700, Olof Johansson wrote:
>> Move a couple of tests and do a minor refactor to avoid:
> []
>> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> []
>> @@ -2926,8 +2928,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>>       INIT_LIST_HEAD(&pd->channels);
>>
>>       /* Initialize channel parameters */
>> -     num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
>> -                     (u8)pi->pcfg.num_chan);
>> +     num_chan = max_t(int, pdat ? pdat->nr_valid_peri :
>> +                                  pi->pcfg.num_peri,
>> +                           pi->pcfg.num_chan);
>>       pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
>
> Few trivial things:
>
> There's no error checking for a malloc failure
> This should probably be kcalloc

Yes, this driver could do with further cleanups, congratulations on
your observations.

All of that is completely unrelated to this patch. Feel free to submit
your own changes to clean up the driver further.

> The alignment here is not nice

Bikeshed much? Let's just remove the ? : instead then. New patch shortly.


-Olof

[PATCH v2] dma: pl330: fix a couple of compilation warnings

[Olof Johansson]

Move a couple of tests and do a minor refactor to avoid:

drivers/dma/pl330.c: In function 'pl330_probe':
drivers/dma/pl330.c:2929:215: warning: comparison of distinct pointer types lacks a cast [enabled by default]
drivers/dma/pl330.c: In function 'pl330_tasklet':
drivers/dma/pl330.c:2250:8: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
drivers/dma/pl330.c:2228:25: note: 'pch' was declared here
drivers/dma/pl330.c:2277:130: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
drivers/dma/pl330.c:2260:25: note: 'pch' was declared here

Signed-off-by: Olof Johansson <olof@lixom.net>
---
 drivers/dma/pl330.c |   25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 282caf11..2ee6e23 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2225,12 +2225,9 @@ static inline void free_desc_list(struct list_head *list)
 {
 	struct dma_pl330_dmac *pdmac;
 	struct dma_pl330_desc *desc;
-	struct dma_pl330_chan *pch;
+	struct dma_pl330_chan *pch = NULL;
 	unsigned long flags;
 
-	if (list_empty(list))
-		return;
-
 	/* Finish off the work list */
 	list_for_each_entry(desc, list, node) {
 		dma_async_tx_callback callback;
@@ -2247,6 +2244,10 @@ static inline void free_desc_list(struct list_head *list)
 		desc->pchan = NULL;
 	}
 
+	/* pch will be unset if list was empty */
+	if (!pch)
+		return;
+
 	pdmac = pch->dmac;
 
 	spin_lock_irqsave(&pdmac->pool_lock, flags);
@@ -2257,12 +2258,9 @@ static inline void free_desc_list(struct list_head *list)
 static inline void handle_cyclic_desc_list(struct list_head *list)
 {
 	struct dma_pl330_desc *desc;
-	struct dma_pl330_chan *pch;
+	struct dma_pl330_chan *pch = NULL;
 	unsigned long flags;
 
-	if (list_empty(list))
-		return;
-
 	list_for_each_entry(desc, list, node) {
 		dma_async_tx_callback callback;
 
@@ -2274,6 +2272,10 @@ static inline void handle_cyclic_desc_list(struct list_head *list)
 			callback(desc->txd.callback_param);
 	}
 
+	/* pch will be unset if list was empty */
+	if (!pch)
+		return;
+
 	spin_lock_irqsave(&pch->lock, flags);
 	list_splice_tail_init(list, &pch->work_list);
 	spin_unlock_irqrestore(&pch->lock, flags);
@@ -2926,8 +2928,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 	INIT_LIST_HEAD(&pd->channels);
 
 	/* Initialize channel parameters */
-	num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
-			(u8)pi->pcfg.num_chan);
+	if (pdat)
+		num_chan = max_t(int, pdat->nr_valid_peri, pi->pcfg.num_chan);
+	else
+		num_chan = max_t(int, pi->pcfg.num_peri, pi->pcfg.num_chan);
+
 	pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
 
 	for (i = 0; i < num_chan; i++) {
-- 
1.7.9.2.359.gebfc2

Re: [PATCH] dma: pl330: fix a couple of compilation warnings

[Joe Perches]

On Sun, 2012-04-08 at 16:24 -0700, Olof Johansson wrote:
> On Sun, Apr 8, 2012 at 2:40 PM, Joe Perches <joe@perches.com> wrote:
> > On Sun, 2012-04-08 at 14:18 -0700, Olof Johansson wrote:
> >> Move a couple of tests and do a minor refactor to avoid:
> > []
> >> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> > []
> >> @@ -2926,8 +2928,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
> >>       INIT_LIST_HEAD(&pd->channels);
> >>
> >>       /* Initialize channel parameters */
> >> -     num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
> >> -                     (u8)pi->pcfg.num_chan);
> >> +     num_chan = max_t(int, pdat ? pdat->nr_valid_peri :
> >> +                                  pi->pcfg.num_peri,
> >> +                           pi->pcfg.num_chan);
> >>       pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
> >
> > Few trivial things:
> >
> > There's no error checking for a malloc failure
> > This should probably be kcalloc
> 
> Yes, this driver could do with further cleanups, congratulations on
> your observations.
> 
> All of that is completely unrelated to this patch. Feel free to submit
> your own changes to clean up the driver further.

No thanks.  It's adjacent to the lines you modify
which is the only reason I noticed.  You might
also notice any patch I submit against the current
tree would conflict with your changes.

It'd be better if you actually fix problems with
the code and not simply make compiler warnings be
silenced when the problem is fundamentally that
the compiler is needs improvements.

Re: [PATCH v2] dma: pl330: fix a couple of compilation warnings

[Vinod Koul]

On Sun, 2012-04-08 at 16:26 -0700, Olof Johansson wrote:
> Move a couple of tests and do a minor refactor to avoid:
> 
> drivers/dma/pl330.c: In function 'pl330_probe':
> drivers/dma/pl330.c:2929:215: warning: comparison of distinct pointer types lacks a cast [enabled by default]
> drivers/dma/pl330.c: In function 'pl330_tasklet':
> drivers/dma/pl330.c:2250:8: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
> drivers/dma/pl330.c:2228:25: note: 'pch' was declared here
> drivers/dma/pl330.c:2277:130: warning: 'pch' may be used uninitialized in this function [-Wuninitialized]
> drivers/dma/pl330.c:2260:25: note: 'pch' was declared here
> 
> Signed-off-by: Olof Johansson <olof@lixom.net>
Applied thanks

> ---
>  drivers/dma/pl330.c |   25 +++++++++++++++----------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 282caf11..2ee6e23 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -2225,12 +2225,9 @@ static inline void free_desc_list(struct list_head *list)
>  {
>  	struct dma_pl330_dmac *pdmac;
>  	struct dma_pl330_desc *desc;
> -	struct dma_pl330_chan *pch;
> +	struct dma_pl330_chan *pch = NULL;
>  	unsigned long flags;
>  
> -	if (list_empty(list))
> -		return;
> -
>  	/* Finish off the work list */
>  	list_for_each_entry(desc, list, node) {
>  		dma_async_tx_callback callback;
> @@ -2247,6 +2244,10 @@ static inline void free_desc_list(struct list_head *list)
>  		desc->pchan = NULL;
>  	}
>  
> +	/* pch will be unset if list was empty */
> +	if (!pch)
> +		return;
> +
>  	pdmac = pch->dmac;
>  
>  	spin_lock_irqsave(&pdmac->pool_lock, flags);
> @@ -2257,12 +2258,9 @@ static inline void free_desc_list(struct list_head *list)
>  static inline void handle_cyclic_desc_list(struct list_head *list)
>  {
>  	struct dma_pl330_desc *desc;
> -	struct dma_pl330_chan *pch;
> +	struct dma_pl330_chan *pch = NULL;
>  	unsigned long flags;
>  
> -	if (list_empty(list))
> -		return;
> -
>  	list_for_each_entry(desc, list, node) {
>  		dma_async_tx_callback callback;
>  
> @@ -2274,6 +2272,10 @@ static inline void handle_cyclic_desc_list(struct list_head *list)
>  			callback(desc->txd.callback_param);
>  	}
>  
> +	/* pch will be unset if list was empty */
> +	if (!pch)
> +		return;
> +
>  	spin_lock_irqsave(&pch->lock, flags);
>  	list_splice_tail_init(list, &pch->work_list);
>  	spin_unlock_irqrestore(&pch->lock, flags);
> @@ -2926,8 +2928,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>  	INIT_LIST_HEAD(&pd->channels);
>  
>  	/* Initialize channel parameters */
> -	num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri,
> -			(u8)pi->pcfg.num_chan);
> +	if (pdat)
> +		num_chan = max_t(int, pdat->nr_valid_peri, pi->pcfg.num_chan);
> +	else
> +		num_chan = max_t(int, pi->pcfg.num_peri, pi->pcfg.num_chan);
> +
>  	pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
>  
>  	for (i = 0; i < num_chan; i++) {


-- 
~Vinod