Re: [PATCH 2/4] pwm: Reduce time the pwm_lock mutex is held in pwmchip_add()

From: Uwe Kleine-König
Date: Thu Nov 17 2022 - 09:00:38 EST


Hello Andy,

On Wed, Nov 16, 2022 at 10:11:32AM +0200, Andy Shevchenko wrote:
> On Tue, Nov 15, 2022 at 10:15:13PM +0100, Uwe Kleine-König wrote:
> > This simplifies error handling as the need for goto error handling goes
> > away and at the end of the function the code can be simplified as this
> > code isn't used in the error case any more.
>
> ...
>
> > + mutex_unlock(&pwm_lock);
> >
> > if (IS_ENABLED(CONFIG_OF))
> > of_pwmchip_add(chip);
>
> Why calling this without a lock is not a problem? Commit message doesn't share
> a bit about this change.

Maybe add another paragraph at the end reading:

Now memory allocation and the call to of_pwmchip_add() are done without
holding the lock. Both don't access the data structures protected by
&pwm_lock.

Best regards
Uwe

--
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