From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: About mmc delayed workqueue. Date: Tue, 29 Mar 2011 19:44:46 -0400 Message-ID: References: <20110329233459.GI27290@trinity.fluff.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from void.printf.net ([89.145.121.20]:50436 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751683Ab1C2Xi5 (ORCPT ); Tue, 29 Mar 2011 19:38:57 -0400 In-Reply-To: <20110329233459.GI27290@trinity.fluff.org> (Ben Dooks's message of "Wed, 30 Mar 2011 00:34:59 +0100") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ben Dooks Cc: NamJae Jeon , linux-mmc@vger.kernel.org Hi, On Tue, Mar 29 2011, Ben Dooks wrote: > On Wed, Mar 30, 2011 at 08:33:12AM +0900, NamJae Jeon wrote: >> Hi. Chris. >> >> I found some problem in mmc driver. As you know, in nand trend, emmc >> nand is used booting device in embededd product. > > yeah, a really nasty trend if you ask me. > >> It means that kernel, rootfs image is stored in emmc nand device. and >> when rescaning mmc, mmc driver is working by delay work queue. >> >> It can be cause "can not mount rootfs". If kernel mounting is faster >> than mmc rescan, this problem would occur.. >> >> I changed to schedule_work instead of mmc_schedule_delayed_work. I can >> make patch & test. >> >> could you tell me your opinion ? > > Use root_wait on the commandline and it will wait for the root device > to become reayd. Ben's right that you should use "rootwait" (I don't think it works with the underscore in the middle), rootdelay=5 if you want the boot to fail if the partition isn't mounted after a little extra time, or an initrd if you want full control over rootfs mounting. These parameters are documented in Documentation/kernel-parameters.txt. Thanks, - Chris. -- Chris Ball One Laptop Per Child