Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753901AbbLJO4i (ORCPT ); Thu, 10 Dec 2015 09:56:38 -0500 Received: from mail-vk0-f43.google.com ([209.85.213.43]:35168 "EHLO mail-vk0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753279AbbLJO4g (ORCPT ); Thu, 10 Dec 2015 09:56:36 -0500 MIME-Version: 1.0 In-Reply-To: <56698FB3.9030705@cogentembedded.com> References: <1449700359-14262-1-git-send-email-geyslan@gmail.com> <1449700359-14262-4-git-send-email-geyslan@gmail.com> <5669680E.4070304@cogentembedded.com> <56698FB3.9030705@cogentembedded.com> Date: Thu, 10 Dec 2015 11:56:35 -0300 Message-ID: Subject: Re: [PATCH 4/9v2] usb: host: ehci.h: fix single statement macros From: "Geyslan G. Bem" To: Sergei Shtylyov Cc: Peter Senna Tschudin , Alan Stern , Greg Kroah-Hartman , linux-usb@vger.kernel.org, LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1947 Lines: 71 2015-12-10 11:44 GMT-03:00 Sergei Shtylyov : > On 12/10/2015 04:05 PM, Geyslan G. Bem wrote: > >>>>> Don't use the 'do {} while (0)' wrapper in a single statement macro. >>>>> >>>>> Caught by checkpatch: "WARNING: Single statement macros should not >>>>> use a do {} while (0) loop" >>>>> >>>>> Signed-off-by: Geyslan G. Bem >>>>> --- >>>>> drivers/usb/host/ehci.h | 4 ++-- >>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h >>>>> index cfeebd8..945000a 100644 >>>>> --- a/drivers/usb/host/ehci.h >>>>> +++ b/drivers/usb/host/ehci.h >>>>> @@ -244,9 +244,9 @@ struct ehci_hcd { /* one per >>>>> controller */ >>>>> /* irq statistics */ >>>>> #ifdef EHCI_STATS >>>>> struct ehci_stats stats; >>>>> -# define COUNT(x) do { (x)++; } while (0) >>>>> +# define COUNT(x) ((x)++) >>>>> #else >>>>> -# define COUNT(x) do {} while (0) >>>>> +# define COUNT(x) ((void) 0) >>>> >>>> >>>> >>>> Why not just empty #define? >>> >>> >>> Indeed. I'll change it. >>> Tks Sergei. >> >> >> Since COUNT is not used to return the empty #define is ok. Another way >> is to use #define COUNT(x) (0) to get a 0 when necessary to read >> returns. > > > Just 0, no parens please. Ok, no parens, since there's no evaluation. Then my change is: -# define COUNT(x) do { (x)++; } while (0) +# define COUNT(x) (++(x)) #else -# define COUNT(x) do {} while (0) +# define COUNT(x) 0 Pre-increment allowing to return the updated x. > > MBR, Sergei > -- Regards, Geyslan G. Bem hackingbits.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/