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Date: Thu, 14 Mar 2013 13:08:34 +0900
Message-ID: <CAKYAXd_v5TsMJ+h3Zk4FRDB0jAfF04t4Z65D1kmB1ziOk65+Vg@mail.gmail.com>
Subject: Re: [PATCH v2] wait while adding MMC host to ensure root mounts
From: Namjae Jeon <linkinjeon@gmail.com>
To: Sergey Yanovich <ynvich@gmail.com>
Cc: Chris Ball <cjb@laptop.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Jaehoon Chung <jh80.chung@samsung.com>, linux-kernel@vger.kernel.org,
        linux-mmc@vger.kernel.org
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2013/3/14, Sergey Yanovich <ynvich@gmail.com>:
> MMC hosts are added asynchronously. We need to wait until detect returns to
> avoid failed root filesystem mounts.
> ---8<---
> VFS: Cannot open root device "mmcblk0p1" or unknown-block(0,0): error -6
> Please append a correct "root=" boot option; here are the available
> partitions:
> mmc0: host does not support reading read-only switch. assuming
> write-enable.
> 1f00             256 mtdblock0  (driver?)
> 1f01             256 mtdblock1  (driver?)
> 1f02            2560 mtdblock2 mmc0: new SDHC card at address b368
>  (driver?)
> 1f03           29696 mtdblock3  (driver?)
> 1f04           16384 mtdblock4 mmcblk0: mmc0:b368 USD   3.72 GiB
>  (driver?)
>  mmcblk0: p1
> b300         3910656 mmcblk0  driver: mmcblk
>   b301         3906560 mmcblk0p1 00000000-01
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,0)
> ---8<---
>
> Signed-off-by: Sergey Yanovich <ynvich@gmail.com>
> ---
Hi.
Have you ever tried to use rootwait or rootdelay on command line ?
If no, You can use them.

Thanks.