linux-kernel - Re: [MMC] Multiple cards on one host

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 3 Sep 2008 16:11:02 +0200
From:	Pierre Ossman <drzeus-mmc@...eus.cx>
To:	Sascha Hauer <s.hauer@...gutronix.de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [MMC] Multiple cards on one host

On Wed, 3 Sep 2008 10:43:43 +0200
Sascha Hauer <s.hauer@...gutronix.de> wrote:

> Hi,
> 
> I have a board (PXA based) which has two SD slots. It uses a gpio to
> switch between the slots. In times when the MMC subsystem implemented
> the bus topology our customer used this fact to connect the two slots on
> a single host (although it was never intended to work with SD cards, it
> seemed to work). Any idea how to implement this on recent kernels? I
> thought about registering two hosts in pxamci.c, but this seems quite
> hacky and I suppose I'll run into locking trouble.
> 

To be honest, I don't think you can sanely support it. The OMAP guys
have been playing with some kind of multiplexer in front of the
controller, but it just seems like a world of hurt to me.

Perhaps you can convert to using SPI for the second slot if the
customer really needs a design with two slots?

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  rdesktop, core developer          http://www.rdesktop.org

  WARNING: This correspondence is being monitored by the
  Swedish government. Make sure your server uses encryption
  for SMTP traffic and consider using PGP for end-to-end
  encryption.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/