Input: stmpe-keypad - remove VLA usage
diff mbox

Message ID 20180309224208.GA7080@embeddedor.com
State Under Review
Headers show

Commit Message

Gustavo A. R. Silva March 9, 2018, 10:42 p.m. UTC
In preparation to enabling -Wvla, remove VLA and replace it
with a fixed-length array instead.

Fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Comments

Dmitry Torokhov March 9, 2018, 11:32 p.m. UTC | #1
On Fri, Mar 09, 2018 at 04:42:08PM -0600, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wvla, remove VLA and replace it
> with a fixed-length array instead.
> 
> Fixed as part of the directive to remove all VLAs from
> the kernel: https://lkml.org/lkml/2018/3/7/621
> 
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/keyboard/stmpe-keypad.c b/drivers/input/keyboard/stmpe-keypad.c
> index 8c6c0b9..cfa1dbe 100644
> --- a/drivers/input/keyboard/stmpe-keypad.c
> +++ b/drivers/input/keyboard/stmpe-keypad.c
> @@ -48,6 +48,8 @@
>  #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
>  	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
>  
> +#define MAX_NUM_DATA			5
> +
>  /**
>   * struct stmpe_keypad_variant - model-specific attributes
>   * @auto_increment: whether the KPC_DATA_BYTE register address
> @@ -74,7 +76,7 @@ struct stmpe_keypad_variant {
>  static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>  	[STMPE1601] = {
>  		.auto_increment		= true,
> -		.num_data		= 5,
> +		.num_data		= MAX_NUM_DATA,
>  		.num_normal_data	= 3,
>  		.max_cols		= 8,
>  		.max_rows		= 8,
> @@ -84,7 +86,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>  	[STMPE2401] = {
>  		.auto_increment		= false,
>  		.set_pullup		= true,
> -		.num_data		= 3,
> +		.num_data		= MAX_NUM_DATA - 2,

Logically MAX_NUM_DATA - 2 does not mean anything, it is simply a way
for you to get to 3, so I'd rather we did not do that.

Can we do

#define STMPE1601_NUM_DATA	5
#define STMPE2401_NUM_DATA	3
#define STMPE2403_NUM_DATA	5
#define MAX_NUM_DATA		max3(STMPE1601_NUM_DATA, \
				     STMPE2401_NUM_DATA, \
				     STMPE2403_NUM_DATA)


or simply

/* Make sure it covers all cases above */
#define MAX_NUM_DATA		5

>  		.num_normal_data	= 2,
>  		.max_cols		= 8,
>  		.max_rows		= 12,
> @@ -94,7 +96,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>  	[STMPE2403] = {
>  		.auto_increment		= true,
>  		.set_pullup		= true,
> -		.num_data		= 5,
> +		.num_data		= MAX_NUM_DATA,
>  		.num_normal_data	= 3,
>  		.max_cols		= 8,
>  		.max_rows		= 12,
> @@ -156,7 +158,7 @@ static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
>  	struct stmpe_keypad *keypad = dev;
>  	struct input_dev *input = keypad->input;
>  	const struct stmpe_keypad_variant *variant = keypad->variant;
> -	u8 fifo[variant->num_data];
> +	u8 fifo[MAX_NUM_DATA];
>  	int ret;
>  	int i;
>  
> -- 
> 2.7.4
> 

Thanks.
Gustavo A. R. Silva March 10, 2018, 3:32 a.m. UTC | #2
Hi Dmitry,

On 03/09/2018 05:32 PM, Dmitry Torokhov wrote:
> On Fri, Mar 09, 2018 at 04:42:08PM -0600, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wvla, remove VLA and replace it
>> with a fixed-length array instead.
>>
>> Fixed as part of the directive to remove all VLAs from
>> the kernel: https://lkml.org/lkml/2018/3/7/621
>>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>>   drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
>>   1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/input/keyboard/stmpe-keypad.c b/drivers/input/keyboard/stmpe-keypad.c
>> index 8c6c0b9..cfa1dbe 100644
>> --- a/drivers/input/keyboard/stmpe-keypad.c
>> +++ b/drivers/input/keyboard/stmpe-keypad.c
>> @@ -48,6 +48,8 @@
>>   #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
>>   	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
>>   
>> +#define MAX_NUM_DATA			5
>> +
>>   /**
>>    * struct stmpe_keypad_variant - model-specific attributes
>>    * @auto_increment: whether the KPC_DATA_BYTE register address
>> @@ -74,7 +76,7 @@ struct stmpe_keypad_variant {
>>   static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>>   	[STMPE1601] = {
>>   		.auto_increment		= true,
>> -		.num_data		= 5,
>> +		.num_data		= MAX_NUM_DATA,
>>   		.num_normal_data	= 3,
>>   		.max_cols		= 8,
>>   		.max_rows		= 8,
>> @@ -84,7 +86,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>>   	[STMPE2401] = {
>>   		.auto_increment		= false,
>>   		.set_pullup		= true,
>> -		.num_data		= 3,
>> +		.num_data		= MAX_NUM_DATA - 2,
> 
> Logically MAX_NUM_DATA - 2 does not mean anything, it is simply a way
> for you to get to 3, so I'd rather we did not do that.
> 

Yeah. I agree.

> Can we do
> 
> #define STMPE1601_NUM_DATA	5
> #define STMPE2401_NUM_DATA	3
> #define STMPE2403_NUM_DATA	5
> #define MAX_NUM_DATA		max3(STMPE1601_NUM_DATA, \
> 				     STMPE2401_NUM_DATA, \
> 				     STMPE2403_NUM_DATA)
> 
> 
> or simply
> 
> /* Make sure it covers all cases above */
> #define MAX_NUM_DATA		5

This one works just fine.

I'll send v2 of this patch shortly.

Thanks for the feedback.
I appreciate it.
--
Gustavo

> 
>>   		.num_normal_data	= 2,
>>   		.max_cols		= 8,
>>   		.max_rows		= 12,
>> @@ -94,7 +96,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
>>   	[STMPE2403] = {
>>   		.auto_increment		= true,
>>   		.set_pullup		= true,
>> -		.num_data		= 5,
>> +		.num_data		= MAX_NUM_DATA,
>>   		.num_normal_data	= 3,
>>   		.max_cols		= 8,
>>   		.max_rows		= 12,
>> @@ -156,7 +158,7 @@ static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
>>   	struct stmpe_keypad *keypad = dev;
>>   	struct input_dev *input = keypad->input;
>>   	const struct stmpe_keypad_variant *variant = keypad->variant;
>> -	u8 fifo[variant->num_data];
>> +	u8 fifo[MAX_NUM_DATA];
>>   	int ret;
>>   	int i;
>>   
>> -- 
>> 2.7.4
>>
> 
> Thanks.
> 


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Patch
diff mbox

diff --git a/drivers/input/keyboard/stmpe-keypad.c b/drivers/input/keyboard/stmpe-keypad.c
index 8c6c0b9..cfa1dbe 100644
--- a/drivers/input/keyboard/stmpe-keypad.c
+++ b/drivers/input/keyboard/stmpe-keypad.c
@@ -48,6 +48,8 @@ 
 #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
 	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
 
+#define MAX_NUM_DATA			5
+
 /**
  * struct stmpe_keypad_variant - model-specific attributes
  * @auto_increment: whether the KPC_DATA_BYTE register address
@@ -74,7 +76,7 @@  struct stmpe_keypad_variant {
 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE1601] = {
 		.auto_increment		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 8,
@@ -84,7 +86,7 @@  static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2401] = {
 		.auto_increment		= false,
 		.set_pullup		= true,
-		.num_data		= 3,
+		.num_data		= MAX_NUM_DATA - 2,
 		.num_normal_data	= 2,
 		.max_cols		= 8,
 		.max_rows		= 12,
@@ -94,7 +96,7 @@  static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2403] = {
 		.auto_increment		= true,
 		.set_pullup		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 12,
@@ -156,7 +158,7 @@  static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
 	struct stmpe_keypad *keypad = dev;
 	struct input_dev *input = keypad->input;
 	const struct stmpe_keypad_variant *variant = keypad->variant;
-	u8 fifo[variant->num_data];
+	u8 fifo[MAX_NUM_DATA];
 	int ret;
 	int i;