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

Uwe Kleine-König
2023-12-08T17:21:57Z

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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

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.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |

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