From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH 1/1] [PATCH v4 1/1] mmc: Support of DUAL BUFFER DESC[ring] mode for dw_mmc Date: Fri, 04 Nov 2011 10:43:21 +0900 Message-ID: <4EB34339.4060809@samsung.com> References: <1317123568-5203-1-git-send-email-shashidharh@vayavyalabs.com> <4E8BBD76.9020001@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout2.samsung.com ([203.254.224.25]:56341 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754460Ab1KDBnq (ORCPT ); Thu, 3 Nov 2011 21:43:46 -0400 Received: from epcpsbgm1.samsung.com (mailout2.samsung.com [203.254.224.25]) by mailout2.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LU4006IC4SDU0C0@mailout2.samsung.com> for linux-mmc@vger.kernel.org; Fri, 04 Nov 2011 10:43:29 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp1.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTPA id <0LU400H0A4SH6B80@mmp1.samsung.com> for linux-mmc@vger.kernel.org; Fri, 04 Nov 2011 10:43:29 +0900 (KST) In-reply-to: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Will Newton Cc: Chris Ball , Shashidhar Hiremath , Jaehoon Chung , Shawn Guo , Wolfram Sang , Philip Rakity , Zhangfei Gao , Will Newton , James Hogan , Kyungmin Park , Matt Fleming , linux-mmc@vger.kernel.org On 11/04/2011 12:18 AM, Will Newton wrote: > On Thu, Nov 3, 2011 at 12:35 PM, Chris Ball wrote: >> Hi, >> >> On Thu, Nov 03 2011, Shashidhar Hiremath wrote: >>> Hi Chris, >>> Can this patch be accepted by criteria that its an additional >>> feature supported by the hardware and hence good to have the support >>> in the driver.Also note the patch has been tested. >> >> I think Will and James should make the call on that. >> >> My own opinion is that it's not usually a good idea to merge code that >> increases complexity for no performance gain; if the feature is actually >> important, someone should find a way to finish it and measure a >> performance gain (the gain can be in any of bandwidth, memory, or >> lower CPU utilization) with it, to prove that the change is worthwhile. > > I'm inclined to agree. I don't want to feel like I am blocking > inclusion of anyone's hard work, but unless there is a clear advantage > for one option over the other I can't see a good reason for merging > it. At present it adds a question to the Kconfig that is pretty much > impossible for the user to answer (do I turn this feature on or off? > what is the advantage of choosing each option?). Maybe, i think we didn't achieve the any advantage with this patch. But i understood that shashidhar's hardware is only supported dual buffer descriptor. So he want to merge this patch. If that is not reason, i also think that didn't need to merge. I didn't see that improve the performance...memory/CPU utilization.. Regards, Jaehoon Chung > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >