Re: [PATCH v6 1/4] mfd: add support for Diolan DLN-2 devices

[Johan Hovold <johan@kernel.org>]

On Tue, Oct 07, 2014 at 09:01:27PM +0300, Octavian Purdila wrote:
> On Tue, Oct 7, 2014 at 8:10 PM, Johan Hovold <johan@kernel.org> wrote:
> > On Mon, Oct 06, 2014 at 03:17:22PM +0300, Octavian Purdila wrote:
> >> On Fri, Oct 3, 2014 at 8:12 PM, Johan Hovold <johan@kernel.org> wrote:
> >> >
> >> > On Thu, Sep 25, 2014 at 07:07:31PM +0300, Octavian Purdila wrote:
> >> > > This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO
> >> > > Master Adapter DLN-2. Details about the device can be found here:
> >> > >
> >>
> >> <snip>
> >>
> >> > > +
> >> > > +             ret = dln2_submit_urb(dln2, dln2->rx_urb[i], GFP_KERNEL);
> >> > > +             if (ret < 0)
> >> > > +                     return ret;
> >> >
> >> > Is it really worth having this helper only to save a couple of lines on
> >> > a dev_err? If you do all resubmissions on completion inline in the
> >> > handler, you only have three places where usb_submit_urb is called.
> >>
> >> I moved the completion in the handler as you suggested. I have kept
> >> the helper, would you prefer to remove it?
> >
> > Moved the "completion"? I was suggesting that the URB resubmission
> > should be done inline the URB completion handler.
> >
> > [ "Completion" may be a little ambiguous. The URB callback is called an
> > URB completion handler. Not be confused with the completion structures
> > you use to wait for responses. ]
> >
> 
> Sorry, I meant to say resubmission instead of completion.
> 
> > It's fine to keep the helper as long as it's clear that the urb has been
> > "cached" and should not be resubmitted (inline) in the completion
> > handler in that case.
> 
> Not sure I follow you here. I kept the helper and I call it from the
> completion handler, from free_rx_slot and from dln2_setup_rx_ubs.

Ah sorry, I was referring to your other helper dln2_rx_transfer().

I still think you should do away with the dln2_submit_urb() helper as
it needlessly hides what's on going without any real gain.

Johan