2019-05-07 14:37:49

by Philippe Schenker

[permalink] [raw]
Subject: [PATCH 2/5] iio: stmpe-adc: Reinit completion struct on begin conversion

From: Philippe Schenker <[email protected]>

In some cases, the wait_completion got interrupted. This caused the
error-handling to mutex_unlock the function. The before turned on
interrupt then got called anyway. In the ISR then completion() was
called causing wrong adc-values returned in a following adc-readout.

Reinitialise completion struct to make sure the counter is zero
when beginning a new adc-conversion.

Signed-off-by: Philippe Schenker <[email protected]>
---

drivers/iio/adc/stmpe-adc.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
index 9ec338ba3440..b3872eb37293 100644
--- a/drivers/iio/adc/stmpe-adc.c
+++ b/drivers/iio/adc/stmpe-adc.c
@@ -65,6 +65,8 @@ static int stmpe_read_voltage(struct stmpe_adc *info,

mutex_lock(&info->lock);

+ reinit_completion(&info->completion);
+
info->channel = (u8)chan->channel;

if (info->channel > STMPE_ADC_LAST_NR) {
@@ -105,6 +107,8 @@ static int stmpe_read_temp(struct stmpe_adc *info,

mutex_lock(&info->lock);

+ reinit_completion(&info->completion);
+
info->channel = (u8)chan->channel;

if (info->channel != STMPE_TEMP_CHANNEL) {
--
2.21.0


2019-05-11 10:16:58

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH 2/5] iio: stmpe-adc: Reinit completion struct on begin conversion

On Tue, 7 May 2019 16:36:12 +0200
Philippe Schenker <[email protected]> wrote:

> From: Philippe Schenker <[email protected]>
>
> In some cases, the wait_completion got interrupted. This caused the
> error-handling to mutex_unlock the function. The before turned on
> interrupt then got called anyway. In the ISR then completion() was
> called causing wrong adc-values returned in a following adc-readout.
>
> Reinitialise completion struct to make sure the counter is zero
> when beginning a new adc-conversion.
>
> Signed-off-by: Philippe Schenker <[email protected]>
Hi Philippe,

To me this looks like a fix that we should consider applying to stable.
However, as it is in the middle of this series I'm not going to take
it via the fast route (during rc's). If people want to backport it
they will have to wait until after the next merge window.
If anyone has an urgent need, then shout in the next week and I'll
pull this version out and we can restructure the set.

Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan

> ---
>
> drivers/iio/adc/stmpe-adc.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> index 9ec338ba3440..b3872eb37293 100644
> --- a/drivers/iio/adc/stmpe-adc.c
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -65,6 +65,8 @@ static int stmpe_read_voltage(struct stmpe_adc *info,
>
> mutex_lock(&info->lock);
>
> + reinit_completion(&info->completion);
> +
> info->channel = (u8)chan->channel;
>
> if (info->channel > STMPE_ADC_LAST_NR) {
> @@ -105,6 +107,8 @@ static int stmpe_read_temp(struct stmpe_adc *info,
>
> mutex_lock(&info->lock);
>
> + reinit_completion(&info->completion);
> +
> info->channel = (u8)chan->channel;
>
> if (info->channel != STMPE_TEMP_CHANNEL) {

2019-05-13 08:05:25

by Philippe Schenker

[permalink] [raw]
Subject: Re: [PATCH 2/5] iio: stmpe-adc: Reinit completion struct on begin conversion

On Sat, 2019-05-11 at 11:08 +0100, Jonathan Cameron wrote:
> On Tue, 7 May 2019 16:36:12 +0200
> Philippe Schenker <[email protected]> wrote:
>
> > From: Philippe Schenker <[email protected]>
> >
> > In some cases, the wait_completion got interrupted. This caused the
> > error-handling to mutex_unlock the function. The before turned on
> > interrupt then got called anyway. In the ISR then completion() was
> > called causing wrong adc-values returned in a following adc-readout.
> >
> > Reinitialise completion struct to make sure the counter is zero
> > when beginning a new adc-conversion.
> >
> > Signed-off-by: Philippe Schenker <[email protected]>
> Hi Philippe,
>
> To me this looks like a fix that we should consider applying to stable.
> However, as it is in the middle of this series I'm not going to take
> it via the fast route (during rc's). If people want to backport it
> they will have to wait until after the next merge window.
> If anyone has an urgent need, then shout in the next week and I'll
> pull this version out and we can restructure the set.
>
> Applied to the togreg branch of iio.git and pushed out as testing
> for the autobuilders to play with it.
>
> Thanks,
>
> Jonathan

Hi Jonathan! I don't think that's necessary. As long as it gets into stable at
some point. Our customer use downstream anyway. Where I'm about to apply it now.

Thanks,
Philippe
>
> > ---
> >
> > drivers/iio/adc/stmpe-adc.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> > index 9ec338ba3440..b3872eb37293 100644
> > --- a/drivers/iio/adc/stmpe-adc.c
> > +++ b/drivers/iio/adc/stmpe-adc.c
> > @@ -65,6 +65,8 @@ static int stmpe_read_voltage(struct stmpe_adc *info,
> >
> > mutex_lock(&info->lock);
> >
> > + reinit_completion(&info->completion);
> > +
> > info->channel = (u8)chan->channel;
> >
> > if (info->channel > STMPE_ADC_LAST_NR) {
> > @@ -105,6 +107,8 @@ static int stmpe_read_temp(struct stmpe_adc *info,
> >
> > mutex_lock(&info->lock);
> >
> > + reinit_completion(&info->completion);
> > +
> > info->channel = (u8)chan->channel;
> >
> > if (info->channel != STMPE_TEMP_CHANNEL) {