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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Wed, 24 Jun 2020 15:53:06 +0300
Message-ID: <CAHp75Vf5ANVRb8ghzdWa1F5U3JaRv9J2mVF8AQ+WwBahQM9Y5A@mail.gmail.com>
Subject: Re: [RESEND PATCH v5 3/5] drivers core: allow probe_err accept
 integer and pointer types
To:     Andrzej Hajda <a.hajda@samsung.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Mark Brown <broonie@kernel.org>,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Daniel Vetter <daniel@ffwll.ch>,
        "open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>
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On Wed, Jun 24, 2020 at 2:41 PM Andrzej Hajda <a.hajda@samsung.com> wrote:
>
> Many resource acquisition functions return error value encapsulated in
> pointer instead of integer value. To simplify coding we can use macro
> which will accept both types of error.
> With this patch user can use:
>         probe_err(dev, ptr, ...)
> instead of:
>         probe_err(dev, PTR_ERR(ptr), ...)
> Without loosing old functionality:
>         probe_err(dev, err, ...)

...

> + * This helper implements common pattern present in probe functions for error
> + * checking: print message if the error is not -EPROBE_DEFER and propagate it.
> + * In case of -EPROBE_DEFER it sets defer probe reason, which can be checked
> + * later by reading devices_deferred debugfs attribute.
> + * It replaces code sequence:
> + *     if (err != -EPROBE_DEFER)
> + *             dev_err(dev, ...);

Btw, we have now %pe. Can you consider to use it?

> + *     return err;
> + * with
> + *     return probe_err(dev, err, ...);
> + *
> + * Returns @err.
> + *
> + */
> +#define probe_err(dev, err, args...) __probe_err(dev, (long)(err), args)

Can't we use PTR_ERR() here?

-- 
With Best Regards,
Andy Shevchenko