linux-kernel - Re: [PATCH v4] pwm: tiehrpwm: Enable pwmchip's parent device before setting configuration

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Message-ID: <2b13ec3e-767f-454a-b344-87b7f1bfafb3@ti.com>
Date: Fri, 23 Jan 2026 20:28:48 +0530
From: "Kumar, Udit" <u-kumar1@...com>
To: Gokul Praveen <g-praveen@...com>, Uwe Kleine-König
	<ukleinek@...nel.org>
CC: <j-keerthy@...com>, <linux-pwm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <n-francis@...com>, <u-kumar1@...com>
Subject: Re: [PATCH v4] pwm: tiehrpwm: Enable pwmchip's parent device before
 setting configuration

Hi Uwe/Gokul,

On 1/21/2026 4:19 PM, Gokul Praveen wrote:
> Hello Uwe,
>
> On 21/01/26 15:48, Uwe Kleine-König wrote:
>> Hello Gokul,
>>
>> On Wed, Jan 21, 2026 at 11:41:34AM +0530, Gokul Praveen wrote:
>>> The period and duty cycle configurations on J7200 and J784S4 SoCs
>>> does not get reflected after setting them using sysfs nodes.
>>> This is because at the end of ehrpwm_pwm_config function,
>>> the put_sync function is called which resets the hardware.
>>>
>>> Hold the PWM controller out of low-power mode during .apply() to
>>> make sure it accepts the writes to its registers.
>>>
>>> This renders the calls to pm_runtime_get_sync() and
>>> pm_runtime_put_sync() in ehrpwm_pwm_config() into no-ops, so
>>> these can be dropped.
>>>
>>> Fixes: 5f027d9b83db("pwm: tiehrpwm: Implement .apply() callback")
>>> Signed-off-by: Gokul Praveen <g-praveen@...com>
>>
>> I applied this patch to
>>
>>     https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux.git 
>> pwm/for-next
>>
>> and will send it during the next merge window. The problem is old
>> (v5.18-rc1~54^2~29 from 2021) and it's late in the development cycle, so
>> I won't bother Linus with it for 6.19.
>>
>
fyi,

We are hitting compilation error with this patch

https://gist.github.com/uditkumarti/d23bc9ee1886bfce70cc76e4b19fbb59


> Thank you for your continued support on this issue as well as for 
> accepting the patch.
>
> Best Regards
> Gokul Praveen
>> Best regards
>> Uwe
>