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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Wed, 15 Nov 2023 11:46:36 +0100
Message-ID: <CACRpkdaBWZyoshaOk-PPZ+gwnNj0o05RLyGNmpmhFez_s=A6Lw@mail.gmail.com>
Subject: Re: [PATCH v3] pinctrl: avoid reload of p state in list iteration
To:     Maria Yu <quic_aiquny@quicinc.com>
Cc:     andy.shevchenko@gmail.com, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org, kernel@quicinc.com,
        stable@vger.kernel.org
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On Wed, Nov 15, 2023 at 11:28=E2=80=AFAM Maria Yu <quic_aiquny@quicinc.com>=
 wrote:

> When in the list_for_each_entry iteration, reload of p->state->settings
> with a local setting from old_state will makes the list iteration in a
> infinite loop.
> The typical issue happened, it will frequently have printk message like:
>   "not freeing pin xx (xxx) as part of deactivating group xxx - it is
> already used for some other setting".
> This is a compiler-dependent problem, one instance was got using Clang
> version 10.0 plus arm64 architecture with linux version 4.19.
>
> Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per=
 device")
> Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
> Cc: stable@vger.kernel.org

Patch applied, I edited the commit message a bit.

Thanks a lot for finding this tricky bug!

Yours,
Linus Walleij