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Message-ID: <60e67c07-7e40-4187-a90a-1be9acdfe757@gmail.com>
Date:   Mon, 11 Apr 2022 22:04:42 +0800
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Subject: Re: [PATCH] iio: stmpe-adc: Fix wait_for_completion_timeout return
 value check
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To:     Philippe Schenker <philippe.schenker@toradex.com>,
        "alexandre.torgue@foss.st.com" <alexandre.torgue@foss.st.com>,
        "linux-stm32@st-md-mailman.stormreply.com" 
        <linux-stm32@st-md-mailman.stormreply.com>,
        "keescook@chromium.org" <keescook@chromium.org>,
        "lars@metafoo.de" <lars@metafoo.de>,
        "jic23@kernel.org" <jic23@kernel.org>,
        "mcoquelin.stm32@gmail.com" <mcoquelin.stm32@gmail.com>,
        "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20220411103032.14038-1-linmq006@gmail.com>
 <8b40cdebc07ff7ca29aa9fc03b8d9c40754ab4bd.camel@toradex.com>
From:   Miaoqian Lin <linmq006@gmail.com>
In-Reply-To: <8b40cdebc07ff7ca29aa9fc03b8d9c40754ab4bd.camel@toradex.com>
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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);