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Date:   Tue, 21 Jun 2022 08:57:34 +0200
From:   Johan Hovold <johan@kernel.org>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     frank zago <frank@zago.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Wolfram Sang <wsa@kernel.org>, USB <linux-usb@vger.kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        linux-i2c <linux-i2c@vger.kernel.org>
Subject: Re: [PATCH v6 2/4] gpio: ch341: add GPIO MFD cell driver for the
 CH341
Message-ID: <YrFr3s50ZMD1Et9W@hovoldconsulting.com>
References: <20220616013747.126051-1-frank@zago.net>
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 <YrBLGMD/Gzfv0W6F@hovoldconsulting.com>
 <CAHp75VfWbC2fbKenuzx6LXjUTApcUKyX6gXd-3Pe31cvrbT7kQ@mail.gmail.com>
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On Mon, Jun 20, 2022 at 06:08:19PM +0200, Andy Shevchenko wrote:
> On Mon, Jun 20, 2022 at 12:26 PM Johan Hovold <johan@kernel.org> wrote:
> > On Wed, Jun 15, 2022 at 08:37:45PM -0500, frank zago wrote:
> 
> ...
> 
> > > +     /* Create an URB for handling interrupt */
> > > +     dev->irq_urb = usb_alloc_urb(0, GFP_KERNEL);
> > > +     if (!dev->irq_urb)
> > > +             return dev_err_probe(&pdev->dev, -ENOMEM, "Cannot allocate the int URB\n");
> >
> > This isn't how dev_err_probe() is used.
> 
> While I agree on the below comment, what does this imply?

That you should only use dev_err_probe() to handle -EPROBE_DEFER. That's
what it is was added for, documented as, and it is what the
implementation still tells you.

I see now that there has recently been some mission creep:

	7065f92255bb ("driver core: Clarify that dev_err_probe() is OK even w/out -EPROBE_DEFER")

I'm not sure I agree with that, but fortunately we don't need to have
that debate in this case due to the below.
 
> > And allocation failures are already logged so just return -ENOMEM here.

Johan