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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <op.vlum8dzo7p4s8u@pikus>
Date:	Mon, 08 Nov 2010 12:22:51 +0100
From:	Michał Nazarewicz <m.nazarewicz@...sung.com>
To:	Toshiharu Okada <toshiharu-linux@....okisemi.com>,
	Andy Isaacson <adi@...apodia.org>
Cc:	Greg Kroah-Hartman <gregkh@...e.de>,
	LKML <linux-kernel@...r.kernel.org>,
	linux-usb <linux-usb@...r.kernel.org>,
	"Wang, Qi" <qi.wang@...el.com>,
	"Wang, Yong Y" <yong.y.wang@...el.com>,
	Andrew <andrew.chih.howe.khor@...el.com>,
	Intel OTC <joel.clark@...el.com>,
	"Foster, Margie" <margie.foster@...el.com>,
	"Ewe, Kok Howg" <kok.howg.ewe@...el.com>
Subject: Re: [PATCH v7] USB device driver of Topcliff PCH

> 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@...apodia.org> 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,  Michał "mina86" Nazarewicz       (o o)
+----[mina86*mina86.com]---[mina86*jabber.org]----ooO--(_)--Ooo--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/