回复: [PATCH v6 2/2] hwrng: starfive: rewor k clk/reset teardown order for JHB100

> -----邮件原件-----
> 发件人: Herbert Xu <[email protected]>
> 发送时间: 2026年7月30日 15:15
> 收件人: Lianfeng Ouyang <[email protected]>
> 抄送: Olivia Mackall <[email protected]>; Rob Herring <[email protected]>;
> Krzysztof Kozlowski <[email protected]>; Conor Dooley
> <[email protected]>; Philipp Zabel <[email protected]>;
> [email protected]; [email protected];
> [email protected]
> 主题: Re: [PATCH v6 2/2] hwrng: starfive: rework clk/reset teardown order for
> JHB100
> 
> On Thu, Jul 23, 2026 at 03:52:06PM +0800, lianfeng.ouyang wrote:
> >
> > +	if (!wait && !mutex_trylock(&trng->lock))
> > +		return -EAGAIN;
> > +
> > +	mutex_lock(&trng->lock);
> 
> Did you actually test this? If mutex_trylock succeeds wouldn't
> the subsequent mutex_lock immediately dead-lock?

sorry, you're absolutely right — this is a bug. mutex_trylock() already acquires 
the lock on success, so the subsequent mutex_lock() would self-deadlock on the 
same execution flow (kernel mutexes are non-recursive). The change was small 
enough that I didn't run a test , but that's no excuse for missing it in review.

I will fix by making the two paths mutually exclusive:
if (!wait) {
	if (!mutex_trylock(&trng->lock))
		return -EAGAIN;
} else {
	mutex_lock(&trng->lock);
}

> Something's wrong with your patches and Sashiko couldn't apply
> them at all:
> 
> https://sashiko.dev/#/patchset/20260723075206.3032-1-lianfeng.ouyang%40st
> arfivetech.com
> 
> Thanks,

It seems that this website did not provide a reason for failed to apply. 
It was possible before v4 version. Is this error related to my code?

> --
> Email: Herbert Xu <[email protected]>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Best Regards,
Lianfeng Ouyang