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From: Chris Ball <cjb@laptop.org>
To: Manoj <manoj.iyer@canonical.com>
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Maxim Levitsky <maximlevitsky@gmail.com>,
	Philip Langdale <philipl@overt.org>
Subject: Re: SDHCI: Ricoh [1180:e823] unable to mount MMC cards.
Date: Thu, 31 Mar 2011 14:33:19 -0400	[thread overview]
Message-ID: <m3vcyzuols.fsf@pullcord.laptop.org> (raw)
In-Reply-To: <4D94C0E5.6070801@canonical.com> (Manoj's message of "Thu, 31 Mar 2011 12:59:01 -0500")

Hi Manoj,

On Thu, Mar 31 2011, Manoj wrote:
> Card did not mount. New dmesg is attached.

Okay.  There's nothing in the log about Ricoh, which probably means that
it bailed out early in the function.  You could add a printk to the top
of ricoh_mmc_fixup_rl5c476() if you want to be really sure that the code
there is getting a chance to run.

I think the likely conclusion is that:

(a) The Ricoh controller has a proprietary MMC function that is stealing
    MMC cards away from the SDHCI controller even though the SDHCI could
    read them if it had a chance to.

(b) We don't know how to turn the MMC controller off, because our old
    method for doing so isn't working on this new 0xe823 model.

I'm adding a few people who've touched this code to CC: in case they
have any ideas on working out how to disable the MMC function.  If you
have contact with Ricoh directly or through a vendor, please ask them
for the PCI configuration writes needed to disable the MMC function on
this model so that you can read MMC cards with the SD interface instead.

Thanks,

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

  reply	other threads:[~2011-03-31 18:27 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4D93AD5C.1070308@canonical.com>
2011-03-30 23:04 ` SDHCI: Ricoh [1180:e823] unable to mount MMC cards Chris Ball
2011-03-30 23:32   ` Manoj
2011-03-30 23:53     ` Chris Ball
2011-03-31 14:12       ` Manoj
2011-03-31 14:43         ` Chris Ball
2011-03-31 14:41           ` Manoj
2011-03-31 15:13             ` Chris Ball
2011-03-31 16:00               ` Manoj
2011-03-31 16:31                 ` Chris Ball
2011-03-31 17:09                   ` Manoj
2011-03-31 17:26                     ` Chris Ball
2011-03-31 17:59                       ` Manoj
2011-03-31 18:33                         ` Chris Ball [this message]
2011-03-31 18:47                           ` Philip Langdale
2011-03-31 14:47           ` Manoj

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