Re: [PATCH v7] USB device driver of Topcliff PCH

[MichaÅ Nazarewicz]

> On Mon, Oct 25, 2010 at 07:24:25PM +0900, Toshiharu Okada wrote:
> > +	if (!list_empty(&ep->queue)) {
> > +		dev_dbg(&dev->pdev->dev, "%s: list not empty", __func__);
> > +		ret = -EAGAIN;
> > +	} else if (!halt) {	/* halt or clear halt */
> > +		pch_udc_ep_clear_stall(ep);
> > +		ret = 0;
> > +	} else {
> > +		if (ep->num == PCH_UDC_EP0)
> > +			ep->dev->stall = 1;
> > +		pch_udc_ep_set_stall(ep);
> > +		pch_udc_enable_ep_interrupts(ep->dev,
> > +					     PCH_UDC_EPINT(ep->in, ep->num));
> > +		ret = 0;
> > +	}

On Wed, 03 Nov 2010 19:37:50 +0100, Andy Isaacson <adi@xxxxxxxxxxxxx> wrote:
> I think this would be clearer as
>
> +	if (!list_empty(&ep->queue)) {
> +		dev_dbg(&dev->pdev->dev, "%s: list not empty", __func__);
> +		ret = -EAGAIN;
> +	}
> +	if (halt) {
> +		if (ep->num == PCH_UDC_EP0)
> +			ep->dev->stall = 1;
> +		pch_udc_ep_set_stall(ep);
> +		pch_udc_enable_ep_interrupts(ep->dev,
> +					     PCH_UDC_EPINT(ep->in, ep->num));
> +		ret = 0;
> +	} else {
> +		pch_udc_ep_clear_stall(ep);
> +		ret = 0;
> +	}

This changes the behavior of the construct though.

> because:
> 1. if (!list_empty  is a standalone check, there is no if/else if/else
> connection between list_empty() and halt.

This depends on how you look at it.  The way I see it is that there are three
mutually exclusive cases: the list is not empty, it is a halt, it is not a
halt.  This way, if-else-if-else seems like a good construct to me.

> 2. I prefer if (foo) {} else {} instead of if (!foo) {} else {}, unless
> there is a significant reason to do the negated test.

I agree on that though.

> > +	pr_debug("%s: %s", __func__, usbep->name);
>
> There are probably too many pr_debug() and dev_dbg()s in this driver.
> Please reconsider which ones are appropriate for mainline.

Do we really care?  Just don't define DEBUG...

--
Best regards,                                        _     _
| Humble Liege of Serenely Enlightened Majesty of  o' \,=./ `o
| Computer Science,  MichaÅ "mina86" Nazarewicz       (o o)
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