linux-kernel - Re: [PATCH v11 1/3] pwm: Export `pwmchip

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Message-ID: <e6d85387-b46e-4e4f-90a3-f60a800f1c2e@samsung.com>
Date: Fri, 11 Jul 2025 11:25:18 +0200
From: Michal Wilczynski <m.wilczynski@...sung.com>
To: Uwe Kleine-König <ukleinek@...nel.org>
Cc: Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor <alex.gaynor@...il.com>,
	Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>, Andreas
	Hindborg <a.hindborg@...nel.org>, Alice Ryhl <aliceryhl@...gle.com>, Trevor
	Gross <tmgross@...ch.edu>, Danilo Krummrich <dakr@...nel.org>, Drew Fustini
	<drew@...7.com>, Guo Ren <guoren@...nel.org>, Fu Wei <wefu@...hat.com>, Rob
	Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor
	Dooley <conor+dt@...nel.org>, Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alex@...ti.fr>, Marek Szyprowski
	<m.szyprowski@...sung.com>, Benno Lossin <lossin@...nel.org>, Michael
	Turquette <mturquette@...libre.com>, Drew Fustini <fustini@...nel.org>,
	linux-kernel@...r.kernel.org, linux-pwm@...r.kernel.org,
	rust-for-linux@...r.kernel.org, linux-riscv@...ts.infradead.org,
	devicetree@...r.kernel.org
Subject: Re: [PATCH v11 1/3] pwm: Export `pwmchip_release` for external use



On 7/10/25 22:52, Uwe Kleine-König wrote:
> Hello Michal,
> 
> On Thu, Jul 10, 2025 at 08:54:28PM +0200, Michal Wilczynski wrote:
>> diff --git a/include/linux/pwm.h b/include/linux/pwm.h
>> index 8cafc483db53addf95591d1ac74287532c0fa0ee..8f0698c09e62b893d63fc258da3c34781183056f 100644
>> --- a/include/linux/pwm.h
>> +++ b/include/linux/pwm.h
>> @@ -478,6 +478,7 @@ static inline bool pwm_might_sleep(struct pwm_device *pwm)
>>  
>>  /* PWM provider APIs */
>>  void pwmchip_put(struct pwm_chip *chip);
>> +void pwmchip_release(struct device *dev);
> 
> I want this in a separate section because "normal" provider don't need
> that. Please add a comment that this is only public for technical
> reasons for the Rust wrappers.

OK, thanks !

> 
> I understand you are eager to get this merged, but still I'd ask you to
> slow down your patch sending frequency. Currently I tend to not apply it
> for v6.17-rc1 as I'd like to have that in next for some time.

Thank you for the feedback. All of your points make perfect sense.

My apologies for the rapid pace of submissions; I will follow your
suggestion and be sure to allow more time for discussion between future
versions.

> 
> With you waiting a bit longer before v11 I would have written that in
> reply to the explanation in the v10 thread and we might have saved
> one iteration ...
> 
>>  struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv);
>>  struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv);
>>  
>> @@ -551,6 +552,10 @@ static inline void pwmchip_put(struct pwm_chip *chip)
>>  {
>>  }
>>  
>> +static inline void pwmchip_release(struct device *dev)
>> +{
>> +}
>> +
> 
> Is this needed? There is no user of this function that doesn't depend
> on CONFIG_PWM?!

Since only Rust is using this it's not needed. Thanks !

> 
>>  static inline struct pwm_chip *pwmchip_alloc(struct device *parent,
>>  					     unsigned int npwm,
>>  					     size_t sizeof_priv)
>>
> 
> Best regards
> Uwe

Best regards,
-- 
Michal Wilczynski <m.wilczynski@...sung.com>