| Message ID | 20220412015547.4137-1-linmq006@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] iio: stmpe-adc: Fix wait_for_completion_timeout return value check | expand |
> -----Original Message----- > From: Miaoqian Lin <linmq006@gmail.com> > Sent: Tuesday, April 12, 2022 3:56 AM > To: Jonathan Cameron <jic23@kernel.org>; Lars-Peter Clausen > <lars@metafoo.de>; Maxime Coquelin > <mcoquelin.stm32@gmail.com>; Alexandre Torgue > <alexandre.torgue@foss.st.com>; Kees Cook > <keescook@chromium.org>; Miaoqian Lin <linmq006@gmail.com>; > Philippe Schenker <philippe.schenker@toradex.com>; linux- > iio@vger.kernel.org; linux-stm32@st-md-mailman.stormreply.com; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org > Subject: [PATCH v2] iio: stmpe-adc: Fix wait_for_completion_timeout > return value check > > [External] > > 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> > --- > changes in v2: > - Fix same issue in stmpe_read_temp. > --- Reviewed-by: Nuno Sá <nuno.sa@analog.com> (I guess the subject also needs tweaking for the preferred format) > drivers/iio/adc/stmpe-adc.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c > index d2d405388499..83e0ac4467ca 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); > @@ -96,7 +96,7 @@ static int stmpe_read_voltage(struct stmpe_adc > *info, > static int stmpe_read_temp(struct stmpe_adc *info, > struct iio_chan_spec const *chan, int *val) > { > - long ret; > + unsigned long ret; > > mutex_lock(&info->lock); > > @@ -114,7 +114,7 @@ static int stmpe_read_temp(struct stmpe_adc > *info, > > ret = wait_for_completion_timeout(&info->completion, > STMPE_ADC_TIMEOUT); > > - if (ret <= 0) { > + if (ret == 0) { > mutex_unlock(&info->lock); > return -ETIMEDOUT; > } > -- > 2.17.1
diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c index d2d405388499..83e0ac4467ca 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); @@ -96,7 +96,7 @@ static int stmpe_read_voltage(struct stmpe_adc *info, static int stmpe_read_temp(struct stmpe_adc *info, struct iio_chan_spec const *chan, int *val) { - long ret; + unsigned long ret; mutex_lock(&info->lock); @@ -114,7 +114,7 @@ static int stmpe_read_temp(struct stmpe_adc *info, ret = wait_for_completion_timeout(&info->completion, STMPE_ADC_TIMEOUT); - if (ret <= 0) { + if (ret == 0) { mutex_unlock(&info->lock); return -ETIMEDOUT; }
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> --- changes in v2: - Fix same issue in stmpe_read_temp. --- drivers/iio/adc/stmpe-adc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)