Re: sun50i-a64-pinctrl WARN_ON drivers/base/dd.c:349

From: Tejun Heo <tj@kernel.org>
To: "André Przywara" <andre.przywara@arm.com>
Cc: Adam Borowski <kilobyte@angband.pl>,
	Icenowy Zheng <icenowy@aosc.xyz>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: sun50i-a64-pinctrl WARN_ON drivers/base/dd.c:349
Date: Mon, 1 May 2017 15:22:02 -0400	[thread overview]
Message-ID: <20170501192202.GE8921@htj.duckdns.org> (raw)
In-Reply-To: <043dc68f-aaec-48e8-4a92-e57d60a8ed08@arm.com>

Hello,

On Sun, Apr 30, 2017 at 12:34:40AM +0100, André Przywara wrote:
> >> If this is a valid use case, we can change devm to repeat till empty
> >> but it's a weird thing to do to allocate from a release function.
> >>
> >> So, something like this.  Only compile tested.
> 
> I was wondering if using devm_*alloc in a _release_ function is valid at
> all, given that it is called as part of the DEFER clean-up routine.
> Looking at pinmux_generic_free_functions() it looks like we could
> replace it with a (non-devm_) kmalloc version and it would still work
> (given we add a kfree at the end).
> Either that or we bail out early if pctldev->num_functions is zero.

I was just throwing the idea but the more I think about it, the less
sense it makes to me.  So, I really think this should be fixed by
dropping dev_kzalloc() call from the release function.  It makes no
sense.

Thanks.

-- 
tejun