Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756670AbbKEScY (ORCPT ); Thu, 5 Nov 2015 13:32:24 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:32962 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750800AbbKEScW (ORCPT ); Thu, 5 Nov 2015 13:32:22 -0500 Subject: Re: [PATCH 3/4] scsi: fix compiler warning for sg To: Andy Shevchenko References: <1446698789-19308-1-git-send-email-okaya@codeaurora.org> <1446698789-19308-3-git-send-email-okaya@codeaurora.org> <563B7180.2000405@codeaurora.org> Cc: linux-scsi , timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, Doug Gilbert , "James E.J. Bottomley" , "linux-kernel@vger.kernel.org" From: Sinan Kaya Message-ID: <563BA0B3.6080506@codeaurora.org> Date: Thu, 5 Nov 2015 13:32:19 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 59 On 11/5/2015 1:07 PM, Andy Shevchenko wrote: >> OK, I didn't know that we had such a macro. To make this look like the other >> >macro, I can do this. >> > >> >static inline u64 mult_frac64(u64 x, u32 numer, u32 denom) >> >{ >> > u64 quot; >> > u64 rem = x % denom; >> > u64 rem2; >> > >> > quot = x; >> > do_div(quot, denom); >> > >> > rem2 = rem * numer; >> > do_div(rem2, denom); >> > >> > return (quot * numer) + rem2; >> >} > Might be I did a wrong smaple, but do_div() returns two values actually. > You perhaps overlooked it and thus wrote something redundant above. > OK, I was looking at example usages in the kernel. The ones I looked always used the first argument as an input & output parameter. I got nervous about overwriting something. void __ndelay(unsigned long long nsecs) { u64 end; nsecs <<= 9; do_div(nsecs, 125); ... } Let's try again. static inline u64 mult_frac64(u64 x, u32 numer, u32 denom) { u64 rem = x % denom; u64 quot = do_div(x, denom); u64 mul = rem * numer; return (quot * numer) + do_div(mul, denom); } I'll do a s/MULDIV/mult_frac64/g to address Timur's concern. -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- 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/