[PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[Rupesh Majhi]

Since commit 5b63d0ae94cc ("compiler-context-analysis: Remove Sparse
support"), __acquires() and __releases() only feed context analysis.
Their argument is parsed before the function body, where only dev is in
scope, so with analysis enabled for this file the build fails:

  error: use of undeclared identifier 'adc'

These helpers take and drop the lock for the ADC_TM driver, which only
sees their declarations in the header. Naming the lock there would
mean exposing struct adc5_chip, and with no annotation at all the
analysis flags the unbalanced locking. Mark both __context_unsafe().

Fixes: baff45179e90 ("iio: adc: Add support for QCOM PMIC5 Gen3 ADC")
Cc: Marco Elver <elver@google.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Assisted-by: LLM
Signed-off-by: Rupesh Majhi <zoone.rupert@gmail.com>
---
v2: explain __context_unsafe() in commit message (Andy)
v1: https://lore.kernel.org/linux-iio/20261003214516.128573-1-zoone.rupert@gmail.com/

Found by building with CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y, which the
driver does not set today. Build tested only, no hardware here.

 drivers/iio/adc/qcom-spmi-adc5-gen3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/qcom-spmi-adc5-gen3.c b/drivers/iio/adc/qcom-spmi-adc5-gen3.c
index c68c6c5f6aca..6a3cabedf4e8 100644
--- a/drivers/iio/adc/qcom-spmi-adc5-gen3.c
+++ b/drivers/iio/adc/qcom-spmi-adc5-gen3.c
@@ -663,7 +663,7 @@ static int adc5_gen3_add_aux_tm_device(struct adc5_chip *adc)
 }
 
 void adc5_gen3_mutex_lock(struct device *dev)
-	__acquires(&adc->lock)
+	__context_unsafe(/* returns with adc->lock held */)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev->parent);
 	struct adc5_chip *adc = iio_priv(indio_dev);
@@ -673,7 +673,7 @@ void adc5_gen3_mutex_lock(struct device *dev)
 EXPORT_SYMBOL_NS_GPL(adc5_gen3_mutex_lock, "QCOM_SPMI_ADC5_GEN3");
 
 void adc5_gen3_mutex_unlock(struct device *dev)
-	__releases(&adc->lock)
+	__context_unsafe(/* releases adc->lock */)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev->parent);
 	struct adc5_chip *adc = iio_priv(indio_dev);

base-commit: 43ffda3c7f8456bbe641ae8249a077a361b97880
-- 
2.43.0

Re: [PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[Andy Shevchenko]

On Wed, Oct 21, 2026 at 08:24:35AM +0300, Rupesh Majhi wrote:
> Since commit 5b63d0ae94cc ("compiler-context-analysis: Remove Sparse
> support"), __acquires() and __releases() only feed context analysis.
> Their argument is parsed before the function body, where only dev is in
> scope, so with analysis enabled for this file the build fails:
> 
>   error: use of undeclared identifier 'adc'
> 
> These helpers take and drop the lock for the ADC_TM driver, which only
> sees their declarations in the header. Naming the lock there would
> mean exposing struct adc5_chip, and with no annotation at all the
> analysis flags the unbalanced locking. Mark both __context_unsafe().
> 
> Fixes: baff45179e90 ("iio: adc: Add support for QCOM PMIC5 Gen3 ADC")

> Cc: Marco Elver <elver@google.com>
> Cc: Bart Van Assche <bvanassche@acm.org>

Move Cc list after the '---' line (similar to the changelog block below),
it will have the same effect on email headers, but won't pollute the commit
message.

> Assisted-by: LLM

As of today we killed that tag, drop it.

> Signed-off-by: Rupesh Majhi <zoone.rupert@gmail.com>
> ---
> v2: explain __context_unsafe() in commit message (Andy)
> v1: https://lore.kernel.org/linux-iio/20261003214516.128573-1-zoone.rupert@gmail.com/
> 
> Found by building with CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y, which the
> driver does not set today. Build tested only, no hardware here.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[Bart Van Assche]

On 10/20/26 10:24 PM, Rupesh Majhi wrote:
> Found by building with CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y, which the
> driver does not set today. Build tested only, no hardware here.
Why doesn't this patch set CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y?
Shouldn't that change be included in this patch?

Thanks,

Bart.

Re: [PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[Rupesh Majhi]

On Wed, Oct 21, 2026 at 08:15:20AM -0700, Bart Van Assche wrote:
> Why doesn't this patch set CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y?
> Shouldn't that change be included in this patch?

Fair point, without it nothing checks these annotations. v3 will enable
it as a separate patch, so the fix can still be backported on its own.

Re: [PATCH v2] iio: adc: qcom-spmi-adc5-gen3: fix lock annotations on mutex helpers

[Jonathan Cameron]

On Wed, 21 Oct 2026 21:19:44 +0300
Rupesh Majhi <zoone.rupert@gmail.com> wrote:

> On Wed, Oct 21, 2026 at 08:15:20AM -0700, Bart Van Assche wrote:
> > Why doesn't this patch set CONTEXT_ANALYSIS_qcom-spmi-adc5-gen3.o=y?
> > Shouldn't that change be included in this patch?  
> 
> Fair point, without it nothing checks these annotations. v3 will enable
> it as a separate patch, so the fix can still be backported on its own.

I think it's unlikely an generic subsystem wide (or broader)
enablement of this will get back ported, so instead
let us treat this as a forwards looking move.
Drop the fixes tag and perhaps include a second patch enabling
the context analysis much more broadly.

I haven't tried yet, but I think you said not much broke?

Jonathan