[PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[Jiale Yao]

The IIO core does not filter duplicate writes to the event enable
attribute. kxcjk1013_write_event_config() already ignores repeated
enable requests, but a repeated disable request still calls
kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
that was not acquired for this request. This can underflow the runtime
PM usage count and trigger a "Runtime PM usage count underflow" warning.

Return early when the requested state already matches ev_enable_state.

Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/iio/accel/kxcjk-1013.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
index 166fb786425f..8994c9e8e048 100644
--- a/drivers/iio/accel/kxcjk-1013.c
+++ b/drivers/iio/accel/kxcjk-1013.c
@@ -1030,7 +1030,7 @@ static int kxcjk1013_write_event_config(struct iio_dev *indio_dev,
 	struct kxcjk1013_data *data = iio_priv(indio_dev);
 	int ret;
 
-	if (state && data->ev_enable_state)
+	if (state == data->ev_enable_state)
 		return 0;
 
 	mutex_lock(&data->mutex);
-- 
2.34.1

Re: [PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[Andy Shevchenko]

On Fri, Sep 25, 2026 at 10:09:43PM +0800, Jiale Yao wrote:
> The IIO core does not filter duplicate writes to the event enable
> attribute. kxcjk1013_write_event_config() already ignores repeated
> enable requests, but a repeated disable request still calls
> kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
> that was not acquired for this request. This can underflow the runtime
> PM usage count and trigger a "Runtime PM usage count underflow" warning.
> 
> Return early when the requested state already matches ev_enable_state.

Sounds like a bug that needs to be fixed and hence Fixes tag to be applied.

-- 
With Best Regards,
Andy Shevchenko

Re:Re: [PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[jiale yao]

At 2026-09-25 22:17:19, "Andy Shevchenko" <andriy.shevchenko@intel.com> wrote:
>On Fri, Sep 25, 2026 at 10:09:43PM +0800, Jiale Yao wrote:
>> The IIO core does not filter duplicate writes to the event enable
>> attribute. kxcjk1013_write_event_config() already ignores repeated
>> enable requests, but a repeated disable request still calls
>> kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
>> that was not acquired for this request. This can underflow the runtime
>> PM usage count and trigger a "Runtime PM usage count underflow" warning.
>> 
>> Return early when the requested state already matches ev_enable_state.
>
>Sounds like a bug that needs to be fixed and hence Fixes tag to be applied.
Sure, I'll add the Fixes tag in v2, 24h later,  for any other comments before sending it.
>
>-- 
>With Best Regards,
>Andy Shevchenko
>

Re: [PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[Jonathan Cameron]

On Fri, 25 Sep 2026 22:38:07 +0800 (CST)
"jiale yao" <19888972804@163.com> wrote:

> At 2026-09-25 22:17:19, "Andy Shevchenko" <andriy.shevchenko@intel.com> wrote:
> >On Fri, Sep 25, 2026 at 10:09:43PM +0800, Jiale Yao wrote:  
> >> The IIO core does not filter duplicate writes to the event enable
> >> attribute. kxcjk1013_write_event_config() already ignores repeated
> >> enable requests, but a repeated disable request still calls
> >> kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
> >> that was not acquired for this request. This can underflow the runtime
> >> PM usage count and trigger a "Runtime PM usage count underflow" warning.
> >> 
> >> Return early when the requested state already matches ev_enable_state.  
> >
> >Sounds like a bug that needs to be fixed and hence Fixes tag to be applied.  
> Sure, I'll add the Fixes tag in v2, 24h later,  for any other comments before sending it.
For a simple request for a fixes tag, I'm also fine with you just
replying with that tag.  b4 will pick it up (though technically in the
wrong place so I'll massage things whilst applying)

Fix looks good to me.

Jonathan

> >
> >-- 
> >With Best Regards,
> >Andy Shevchenko
> >  

Re:Re: [PATCH] iio: accel: kxcjk-1013: reject duplicate event disable

[jiale yao]

At 2026-09-26 08:49:42, "Jonathan Cameron" <jic23@kernel.org> wrote:
>On Fri, 25 Sep 2026 22:38:07 +0800 (CST)
>"jiale yao" <19888972804@163.com> wrote:
>
>> At 2026-09-25 22:17:19, "Andy Shevchenko" <andriy.shevchenko@intel.com> wrote:
>> >On Fri, Sep 25, 2026 at 10:09:43PM +0800, Jiale Yao wrote:  
>> >> The IIO core does not filter duplicate writes to the event enable
>> >> attribute. kxcjk1013_write_event_config() already ignores repeated
>> >> enable requests, but a repeated disable request still calls
>> >> kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
>> >> that was not acquired for this request. This can underflow the runtime
>> >> PM usage count and trigger a "Runtime PM usage count underflow" warning.
>> >> 
>> >> Return early when the requested state already matches ev_enable_state.  
>> >
>> >Sounds like a bug that needs to be fixed and hence Fixes tag to be applied.  
>> Sure, I'll add the Fixes tag in v2, 24h later,  for any other comments before sending it.
>For a simple request for a fixes tag, I'm also fine with you just
>replying with that tag.  b4 will pick it up (though technically in the
>wrong place so I'll massage things whilst applying)
Thanks.
Fixes: b4b491c0832e ("iio: accel: kxcjk-1013: Support thresholds")
>
>Fix looks good to me.
>
>Jonathan
>
>> >
>> >-- 
>> >With Best Regards,
>> >Andy Shevchenko
>> >