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Message-ID: <44F85646.4030100@mauve.plus.com>
Date: Fri, 01 Sep 2006 16:48:22 +0100
From: Ian Stirling <ian.stirling@mauve.plus.com>
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To: Pierre Ossman <drzeus-list@drzeus.cx>
CC: madhu chikkature <crmadhu210@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: SDIO card support in Linux
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Pierre Ossman wrote:
> madhu chikkature wrote:
>> Hi,
>>
>> This is regarding the discussion going on in the list about the
>> support of SDIO cards in Linux. I read some discussion happening to
>> support SDIO cards using the existing Linux MMC core but I could not
>> figure out what would be the direction the community to support the
>> SDIO cards.
<snip>
>> With this, is it a fissible solution to have the MMC core do the
>> initialization part of the card by having the CMD sequence for SDIO
>> card (CMD5 and CMD3) in the mmc_setup sequence and maintain the SDIO
>> card list along with MMC/SD?
>>
> 
> SD mandates a star topology (just a single card per bus), so we'll just
> force a single card into the list. SD memory cards can actually work on
> a shared bus, SDIO can not. It's not a big problem in practice though.

Is this true in SD-1 bit mode, or SPI?
I see nothing on a quick read-through of the abbreviated SDIO spec 
precluding  this.
Of course, it'd mean wire-or'd interrupt lines.

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