Comment 7 for bug 717435

It appears that this patch appears to enable the card reader, it fails to mount/use/unmount MMC cards successfully. We are seeing failures on two Toshiba R850 (Intel and AMD) laptops with the 11.04 release of Natty.

The output from lspci is:
 * System peripheral: Ricoh Co Ltd Device e823 (rev 04)

It appears to be a known issue according to:

 * http://groups.google.com/group/linux.kernel/browse_thread/thread/81d5997647563887?pli=1

And it doesn't appear others have reported successfully using MMC.

-- cut and paste from the URL above --

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.

-- end copy and paste --