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

From: Andy Shevchenko
Date: Thu Nov 17 2022 - 10:34:07 EST


On Thu, Nov 17, 2022 at 03:00:24PM +0100, Uwe Kleine-König wrote:
> 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.

Good to me, with that added
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

--
With Best Regards,
Andy Shevchenko