From mboxrd@z Thu Jan 1 00:00:00 1970 From: Per Forlin Subject: Re: [PATCH] mmc: support BKOPS feature for eMMC Date: Thu, 27 Oct 2011 19:35:55 +0000 (UTC) Message-ID: 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 lo.gmane.org ([80.91.229.12]:50087 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751754Ab1J0TkK (ORCPT ); Thu, 27 Oct 2011 15:40:10 -0400 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1RJVo8-00078V-8V for linux-mmc@vger.kernel.org; Thu, 27 Oct 2011 21:40:08 +0200 Received: from 57.79.167.152 ([57.79.167.152]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 27 Oct 2011 21:40:08 +0200 Received: from per.lkml by 57.79.167.152 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 27 Oct 2011 21:40:08 +0200 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Jaehoon Chung samsung.com> writes: > +++ 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); > } >=20 > +/** > + * 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 pre= ferable to run bkops periodically and only when the card is idle to minimize th= e risk of reaching URGENT. The specs says: ----- Hosts shall still read the full status from the BKOPS_STATUS byte perio= dically and start background operations as needed. ----- I'm thinking of checking BKOPS_STATUS when the card is idle and then ru= n bkops even if level is only 1 (Operations outstanding =E2=80=93 non critical)= =2E Would this make sense? Regards, Per