diff mbox series

iio: stmpe-adc: Fix wait_for_completion_timeout return value check

Message ID 20220411103032.14038-1-linmq006@gmail.com (mailing list archive)
State Superseded
Headers show
Series iio: stmpe-adc: Fix wait_for_completion_timeout return value check | expand

Commit Message

Miaoqian Lin April 11, 2022, 10:30 a.m. UTC
wait_for_completion_timeout() returns unsigned long not long.
it returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case

Fixes: e813dde6f833 ("iio: stmpe-adc: Use wait_for_completion_timeout")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/iio/adc/stmpe-adc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Philippe Schenker April 11, 2022, 12:05 p.m. UTC | #1
On Mon, 2022-04-11 at 10:30 +0000, Miaoqian Lin wrote:
> wait_for_completion_timeout() returns unsigned long not long.
> it returns 0 if timed out, and positive if completed.
> The check for <= 0 is ambiguous and should be == 0 here
> indicating timeout which is the only error case

Hello and thanks for your fix. Any specific reason you didn't apply this
also in function stmpe_read_temp?

Philippe

> 
> Fixes: e813dde6f833 ("iio: stmpe-adc: Use
> wait_for_completion_timeout")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  drivers/iio/adc/stmpe-adc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> index d2d405388499..d475d1c17bfc 100644
> --- a/drivers/iio/adc/stmpe-adc.c
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -61,7 +61,7 @@ struct stmpe_adc {
>  static int stmpe_read_voltage(struct stmpe_adc *info,
>                 struct iio_chan_spec const *chan, int *val)
>  {
> -       long ret;
> +       unsigned long ret;
>  
>         mutex_lock(&info->lock);
>  
> @@ -79,7 +79,7 @@ static int stmpe_read_voltage(struct stmpe_adc
> *info,
>  
>         ret = wait_for_completion_timeout(&info->completion,
> STMPE_ADC_TIMEOUT);
>  
> -       if (ret <= 0) {
> +       if (ret == 0) {
>                 stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA,
>                                 STMPE_ADC_CH(info->channel));
>                 mutex_unlock(&info->lock);
Miaoqian Lin April 11, 2022, 2:04 p.m. UTC | #2
On 2022/4/11 20:05, Philippe Schenker wrote:
> On Mon, 2022-04-11 at 10:30 +0000, Miaoqian Lin wrote:
>> wait_for_completion_timeout() returns unsigned long not long.
>> it returns 0 if timed out, and positive if completed.
>> The check for <= 0 is ambiguous and should be == 0 here
>> indicating timeout which is the only error case
> Hello and thanks for your fix. Any specific reason you didn't apply this
> also in function stmpe_read_temp?

Hi,sorry I just missed that. I will send v2 to fix this.


>> Fixes: e813dde6f833 ("iio: stmpe-adc: Use
>> wait_for_completion_timeout")
>> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
>> ---
>>  drivers/iio/adc/stmpe-adc.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
>> index d2d405388499..d475d1c17bfc 100644
>> --- a/drivers/iio/adc/stmpe-adc.c
>> +++ b/drivers/iio/adc/stmpe-adc.c
>> @@ -61,7 +61,7 @@ struct stmpe_adc {
>>  static int stmpe_read_voltage(struct stmpe_adc *info,
>>                 struct iio_chan_spec const *chan, int *val)
>>  {
>> -       long ret;
>> +       unsigned long ret;
>>  
>>         mutex_lock(&info->lock);
>>  
>> @@ -79,7 +79,7 @@ static int stmpe_read_voltage(struct stmpe_adc
>> *info,
>>  
>>         ret = wait_for_completion_timeout(&info->completion,
>> STMPE_ADC_TIMEOUT);
>>  
>> -       if (ret <= 0) {
>> +       if (ret == 0) {
>>                 stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA,
>>                                 STMPE_ADC_CH(info->channel));
>>                 mutex_unlock(&info->lock);
diff mbox series

Patch

diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
index d2d405388499..d475d1c17bfc 100644
--- a/drivers/iio/adc/stmpe-adc.c
+++ b/drivers/iio/adc/stmpe-adc.c
@@ -61,7 +61,7 @@  struct stmpe_adc {
 static int stmpe_read_voltage(struct stmpe_adc *info,
 		struct iio_chan_spec const *chan, int *val)
 {
-	long ret;
+	unsigned long ret;
 
 	mutex_lock(&info->lock);
 
@@ -79,7 +79,7 @@  static int stmpe_read_voltage(struct stmpe_adc *info,
 
 	ret = wait_for_completion_timeout(&info->completion, STMPE_ADC_TIMEOUT);
 
-	if (ret <= 0) {
+	if (ret == 0) {
 		stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA,
 				STMPE_ADC_CH(info->channel));
 		mutex_unlock(&info->lock);