From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH v2] mmc: Resolve BKOPS compatability issue Date: Mon, 02 Feb 2015 11:00:16 +0900 Message-ID: <54CEDA30.206@samsung.com> References: <1422521383-11436-1-git-send-email-alexey.skidanov@sandisk.com> <54CB3237.2050207@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:12212 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753662AbbBBCAT (ORCPT ); Sun, 1 Feb 2015 21:00:19 -0500 Received: from epcpsbgr2.samsung.com (u142.gpu120.samsung.co.kr [203.254.230.142]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NJ400E9DG8H6S70@mailout3.samsung.com> for linux-mmc@vger.kernel.org; Mon, 02 Feb 2015 11:00:17 +0900 (KST) In-reply-to: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: Alexey Skidanov , Chris Ball , linux-mmc , Alex Lemberg Hi, On 01/30/2015 07:25 PM, Ulf Hansson wrote: > On 30 January 2015 at 08:26, Jaehoon Chung wrote: >> Hi, Alexey. >> >> On 01/29/2015 05:49 PM, Alexey Skidanov wrote: >>> This patch is coming to fix compatibility issue of BKOPS_EN field of EXT_CSD. >>> In eMMC-5.1, BKOPS_EN was changed, and now it has two operational bits: >>> Bit 0 - MANUAL_EN >>> Bit 1 - AUTO_EN >>> In previous eMMC revisions, only Bit 0 was supported. >> >> If "manual enable" is the same functionality with previous enable, >> I think it doesn't need to change the name.. >> Just checking whether enable or not with Mask bit? >> >> If need to add the auto enable, only add the bkops_auto_en in future. >> This is just my preference..and i don't read the spec since i don't have eMMC5.1 spec. >> >> If manual-enable is difference with previous enable, how about using bkops-manual-en? > > According to information I have got around the eMMC 5.1 spec, the old > value of MAN_EN will remain. That also means that bit will remain as > one time programmable. > > The new AUTO_EN bit, will be multiple writeable with value kept after > power failure. But more importantly, the card seems to expect the host > to disable AUTO_EN before power failure. In other words we need to > disable AUTO_EN (if set) before entering system PM state an cutting > power to the card. Thanks for information.. I want to get this information, I think auto_en bit can be used usefully. Best Regards, Jaehoon Chung > > So, yes, we will have to deal with AUTO_EN sooner or later, thus I am > kind of happy Alexey's patch, as is. > > Kind regards > Uffe >