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Subject: Re: [RESEND PATCH v5 3/5] drivers core: allow probe_err accept
 integer and pointer types
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Jernej Skrabec <jernej.skrabec@siol.net>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Mark Brown <broonie@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>
From:   Andrzej Hajda <a.hajda@samsung.com>
Message-ID: <bbc5ad3e-0e0a-83e1-ed64-e5275b605174@samsung.com>
Date:   Wed, 24 Jun 2020 15:12:55 +0200
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On 24.06.2020 14:53, Andy Shevchenko wrote:
> 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?


OK, I haven't noticed it finally appeared.


>
>> + *     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?


Nope, I want to accept both types: int and pointer.


Regards

Andrzej


>