Re: [PATCH v6 2/4] gpio: ch341: add GPIO MFD cell driver for the CH341

[Johan Hovold <johan@xxxxxxxxxx>]

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@xxxxxxxxxx> 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