From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH] mmc: support BKOPS feature for eMMC Date: Fri, 28 Oct 2011 14:14:13 +0900 Message-ID: <4EAA3A25.60905@samsung.com> References: <4EA93C08.9030009@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:16057 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751253Ab1J1FOY (ORCPT ); Fri, 28 Oct 2011 01:14:24 -0400 Received: from epcpsbgm1.samsung.com (mailout1.samsung.com [203.254.224.24]) by mailout1.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LTR002ZVFVFJJE0@mailout1.samsung.com> for linux-mmc@vger.kernel.org; Fri, 28 Oct 2011 14:14:22 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTPA id <0LTR00BG2FVYZ940@mmp2.samsung.com> for linux-mmc@vger.kernel.org; Fri, 28 Oct 2011 14:14:22 +0900 (KST) In-reply-to: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Per Forlin Cc: linux-mmc@vger.kernel.org On 10/28/2011 04:35 AM, Per Forlin wrote: > Jaehoon Chung samsung.com> writes: >=20 >> +++ b/drivers/mmc/core/core.c >> @@ -238,6 +238,50 @@ mmc_start_request(struct mmc_host *host, struct > mmc_request *mrq) >> host->ops->request(host, mrq); >> } >> >> +/** >> + * mmc_start_bkops - start BKOPS for supported cards >> + * @card: MMC card to start BKOPS >> + * >> + * Start background operations whenever requested. >> + * when the urgent BKOPS bit is set in a R1 command response >> + * then background operations should be started immediately. >> +*/ > This patch only starts BKOPS if it's urgent or critical. I would be p= referable > to run bkops periodically and only when the card is idle to minimize = the risk of > reaching URGENT. >=20 > The specs says: > ----- > Hosts shall still read the full status from the BKOPS_STATUS byte per= iodically > and start background operations as needed. > ----- >=20 > I'm thinking of checking BKOPS_STATUS when the card is idle and then = run bkops > even if level is only 1 (Operations outstanding =E2=80=93 non critica= l). Would this make > sense? >=20 host shall check the BKOPS_STATUS periodically..i will add this point.. (i think that need to check EXT_CSD register periodically.) Thanks, Jaehoon Chung > Regards, > Per >=20 >=20 > -- > 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 >=20