linux-kernel - Re: [PATCH v2] pwm: tiehrpwm: Enable EHRPWM controller before setting configuration

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Message-ID: <hjiyxkzimydqjrtte6r5kemfthwdmhtkysplsptm3npgwqiv4b@d6vlu2fhks37>
Date: Thu, 8 Jan 2026 19:10:48 +0100
From: Uwe Kleine-König <ukleinek@...nel.org>
To: Gokul Praveen <g-praveen@...com>
Cc: "Rafael V. Volkmer" <rafael.v.volkmer@...il.com>, j-keerthy@...com, 
	linux-kernel@...r.kernel.org, linux-pwm@...r.kernel.org, n-francis@...com, u-kumar1@...com
Subject: Re: [PATCH v2] pwm: tiehrpwm: Enable EHRPWM controller before
 setting configuration

Hello Gokul,

On Thu, Jan 08, 2026 at 12:10:35PM +0530, Gokul Praveen wrote:
> On 08/01/26 01:17, Rafael V. Volkmer wrote:
> > Thanks for CC'ing me on this thread.
> > 
> > On 07/01/26 15:21, Uwe Kleine-König wrote:
> > > adding Rafael to Cc: who sent a patch series for this driver that I
> > > didn't come around to review yet. Given that neither he nor me noticed
> > > the problem addressed in this patch I wonder if it applies to all
> > > hardware variants.
> > > 
> > 
> > I also didn't observe the issue described here in my testing: duty cycle and
> > period changes always appeared to take effect as expected.
> > 
> > My tests were done on an AM623 EVM.
> > 
> > One possible explanation is that my test flow mostly exercised configuration
> > while the PWM was already enabled/active, which could mask the effect of a
> > put_sync/reset happening after configuration.
> > 
> 
> Yes, this is the reason why the configuration was taking effect for you ,
> Rafael, as the PWM was already enabled when setting the configuration hence
> masking the effect of a put_sync/reset happening after configuration.

Can you provide a list of commands that show the failure? That would
result in less guessing for me. My plan is to reproduce the failure
tomorrow to better understand it on my boneblack.

Best regards
Uwe

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