Re: [PATCH v6 3/4] pwm: bcm2835: allow pwm driver to be used in atomic context

From: Sean Young <sean@mess.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	linux-media@vger.kernel.org, linux-pwm@vger.kernel.org,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>,
	Florian Fainelli <florian.fainelli@broadcom.com>,
	Broadcom internal kernel review list
	<bcm-kernel-feedback-list@broadcom.com>,
	Ray Jui <rjui@broadcom.com>,
	Scott Branden <sbranden@broadcom.com>,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 3/4] pwm: bcm2835: allow pwm driver to be used in atomic context
Date: Sat, 9 Dec 2023 09:11:17 +0000	[thread overview]
Message-ID: <ZXQvNfLy9mySdrfM@gofer.mess.org> (raw)
In-Reply-To: <20231208172040.mgw7aicmwlw6yjyb@pengutronix.de>

On Fri, Dec 08, 2023 at 06:20:40PM +0100, Uwe Kleine-König wrote:
> On Fri, Dec 08, 2023 at 05:01:26PM +0000, Sean Young wrote:
> > On Fri, Dec 08, 2023 at 05:22:52PM +0100, Thierry Reding wrote:
> > > On Wed, Nov 29, 2023 at 09:13:36AM +0000, Sean Young wrote:
> > > > clk_get_rate() may do a mutex lock. Fetch the clock rate once, and prevent
> > > > rate changes using clk_rate_exclusive_get().
> > > > 
> > > > Signed-off-by: Sean Young <sean@mess.org>
> > > > ---
> > > >  drivers/pwm/pwm-bcm2835.c | 31 +++++++++++++++++++++----------
> > > >  1 file changed, 21 insertions(+), 10 deletions(-)
> > > 
> > > s/pwm/PWM/ in the subject. Although, I guess you could just drop the
> > > "PWM" altogether because the subject prefix implies that this is for
> > > PWM.
> > 
> > $ git log --no-merges --oneline drivers/pwm/ | sed -r 's/^\w* ([^:]+): .*/\1/' | sort | uniq -c
> >    1197 pwm
> >       1 PWM
> >   ...
> > 
> > The vast majority of the commits use pwm: as a prefix, only one uses PWM:. 
> > In fact if you look across the tree almost everywhere lower case is used
> > for the prefix.
> 
> Thierry doesn't want you to change the subject prefix, but only the
> second "pwm" to make it read:
> 
> 	pwm: bcm2835: allow PWM driver to be used in atomic context

Ah of course, my bad.

> While I understand Thierry here, I'm fine with a lowercase pwm here,
> too. In my book a PWM in all uppercase is the type of hardware and pwm
> in all lowercase is the framework's name. If you use "PWM driver" or
> "pwm driver" then doesn't matter much.
> 
> 	
> > 
> > I'm just trying to follow convention.
> > 
> > Having said that, I think the prefix is totally redundant, it is clear from
> > the commit files what they are affecting. I am not sure what it really adds.
> > 
> > > Also, please capitalize after the subject prefix.
> > 
> > $ git log --no-merges --oneline drivers/pwm/ | grep -E '^\w* ([^:]+): [A-Z]' | wc -l
> > 217
> > $ git log --no-merges --oneline drivers/pwm/ | grep -E '^\w* ([^:]+): [a-z]' | wc -l
> > 1069
> 
> Your matching things like:
> 
> 	pwm: pwm-tiehrpwm: Add support for configuring polarity of PWM
> 
> with the second command. These are perfectly fine as pwm-tiehrpwm is the
> driver name and so shouldn't be capitalized. With a bit more care here,
> we get:
> 
> 	$ git log --no-merges --oneline drivers/pwm/ | grep -E '^.+: [a-z][^:]*$' | wc -l
> 	114
> 	$ git log --no-merges --oneline drivers/pwm/ | grep -E '^.+: [A-Z][^:]*$' | wc -l
> 	1167
> 
> And the newest of the 114 with a small letter is from 2013.

Again, I stand corrected.

Thanks for pointing it out, I will fix in the next version.

Sean