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From: Chris Ball <cjb@laptop.org>
To: Ben Dooks <ben@trinity.fluff.org>
Cc: NamJae Jeon <linkinjeon@gmail.com>, linux-mmc@vger.kernel.org
Subject: Re: About mmc delayed workqueue.
Date: Tue, 29 Mar 2011 19:44:46 -0400	[thread overview]
Message-ID: <m3sju58pap.fsf@pullcord.laptop.org> (raw)
In-Reply-To: <20110329233459.GI27290@trinity.fluff.org> (Ben Dooks's message of "Wed, 30 Mar 2011 00:34:59 +0100")

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   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child

  reply	other threads:[~2011-03-29 23:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-29 23:33 About mmc delayed workqueue NamJae Jeon
2011-03-29 23:34 ` Ben Dooks
2011-03-29 23:44   ` Chris Ball [this message]
     [not found]     ` <AANLkTi=5R9w0k_Hg=htyDc=aQDA+t1HOLvWtfAOvMo+z@mail.gmail.com>
2011-03-30  0:40       ` NamJae Jeon
2011-03-30  2:17       ` Chris Ball
2011-03-30  5:10         ` NamJae Jeon

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