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From: Greg KH <greg@kroah.com>
To: Lucas Tanure <tanure@linux.com>
Cc: kernelnewbies <kernelnewbies@kernelnewbies.org>,
	"Billie Alsup \(balsup\)" <balsup@cisco.com>
Subject: Re: Simple mutex_destroy question
Date: Thu, 20 Nov 2025 14:43:58 +0100	[thread overview]
Message-ID: <2025112047-untimely-ducky-a78f@gregkh> (raw)
In-Reply-To: <CAJX_Q+2FgynWMfWdMURL2HbYv3iXFKZ7VgDbZyOUmc9MY_O4vQ@mail.gmail.com>

On Thu, Nov 20, 2025 at 10:27:06AM +0000, Lucas Tanure wrote:
> On Wed, Nov 19, 2025 at 4:27 PM Billie Alsup (balsup) <balsup@cisco.com> wrote:
> >
> > Since you're using devm_kzalloc, why not simply use devm_mutex_init and not worry about it?  Then you can remove your explicit mutex_destroy call.
> 
> I am developing drivers for Android 13 with kernel 5.10/5.4, which
> doesn't have devm_mutex_init.

No new devices should be shipping with Android13 as it is about to go
end-of-life, so please do NOT target these old kernels.

Do your development on the latest kernel release, get your changes
upstream, and then, if you need to apply them to a device-specific
kernel, backport it to that older kernel.  That way is much simpler and
easier and will save you time.

> So, mutex_destroy is only needed for debugging locks? I see a few
> drivers don't have this call in their remove functions or in fail
> probe paths.

Then those are probably bugs that should be fixed up.

thanks,

greg k-h

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      reply	other threads:[~2025-11-20 13:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-23 16:47 Rust: how to implement file_operations for a misc device? Fabio
2025-09-24 10:27 ` Greg KH
2025-11-14 10:42   ` Simple mutex_destroy question Lucas Tanure
2025-11-19 10:08     ` Lucas Tanure
2025-11-19 13:08       ` Raka Gunarto
2025-11-19 16:27     ` Billie Alsup (balsup)
2025-11-20 10:27       ` Lucas Tanure
2025-11-20 13:43         ` Greg KH [this message]

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