Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220606111316.19265-1-ddrokosov@sberdevices.ru>
In-Reply-To: <20220606111316.19265-1-ddrokosov@sberdevices.ru>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Mon, 6 Jun 2022 14:42:18 +0200
Message-ID: <CAHp75VfRF=NyU9TN0FJ=cj0w_C-cKL+foa+WskwpoBP9b+SfDA@mail.gmail.com>
Subject: Re: [PATCH v2] iio: trigger: warn about non-registered iio trigger
 getting attempt
To:     Dmitry Rokosov <DDRokosov@sberdevices.ru>
Cc:     "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "jic23@kernel.org" <jic23@kernel.org>,
        "lars@metafoo.de" <lars@metafoo.de>,
        "noname.nuno@gmail.com" <noname.nuno@gmail.com>,
        "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
        kernel <kernel@sberdevices.ru>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Mon, Jun 6, 2022 at 1:23 PM Dmitry Rokosov <DDRokosov@sberdevices.ru> wrote:
>
> As a part of patch series about wrong trigger register() and get()
> calls order in the some IIO drivers trigger initialization path:
>
> https://lore.kernel.org/all/20220524181150.9240-1-ddrokosov@sberdevices.ru/
>
> runtime WARN() is added to alarm IIO driver authors who make such
> a mistake.
>
> When IIO driver allocates a new IIO trigger, it should register it before

an IIO

> calling the get() operation. In other words, each IIO driver must abide by
> IIO trigger alloc()/register()/get() calls order.

I believe triggers usually acquired at ->probe() time, means that in
case if the following code (however, I believe it will be quite rare)
goes into deferred probe cycle the WARN will be repeated. Perhaps
WARN_ONCE() ?

-- 
With Best Regards,
Andy Shevchenko